Facilities > VLBA > Proposing

Proposing

by Amy Mioduszewski last modified Jan 10, 2018 by Walter Brisken

Additional VLBI Opportunities

by Amy Mioduszewski last modified Jan 04, 2013

Additional VLBI Opportunities

Additional VLBI Opportunities

The VLBA is a stand-alone VLBI array that is useful for addressing many scientific questions. However, in some cases, more sensitive telescopes, longer baselines, or additional high-frequency antennas are necessary to reach science goals. Some additional opportunities are described in the following links:

arecibo.jpg

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VLBA Proposal Preparation and Submission

by Gustaaf Van Moorsel last modified Dec 02, 2015 by Amy Mioduszewski
VLBA Proposal Preparation and Submission

Call for Proposals

The Call for Proposals details the general capabilities being offered for the Very Long Baseline Array (VLBA).  Proposals for time on the VLBA need to be prepared using the Proposal Submission Tool (PST), which is also used to submit proposals for the Very Large Array (VLA) and the Green Bank Telescope (GBT).

In addition to these general capabilities, NRAO offers a VLBA Resident Shared Risk Observing (RSRO) program for those who would like to push the capabilities of the instrument beyond those offered for general use.  Details are available on the web at the VLBA RSRO Program page.

The NRAO Proposal Submission Tool (PST) is accessed via the NRAO Interactive Services.  Documentation is available in the NRAO Proposal Submission Guide. For a comprehensive description of the VLBA instrument we refer to the VLBA Observational Status Summary (OSS).

For questions on the proposal submission process or problems with the NRAO PST please submit a ticket through the NRAO Helpdesk.

How to Propose

  1. Develop rationale: Before writing a proposal, the proposer must develop the scientific rationale for the program, develop a source list, decide on the observing band(s) to be used, and estimate the expected source strengths and their detectability. For spectral-line sources, the proposer also must decide on the desired velocity resolution, and convert that to a spectral resolution.
  2. Create Proposal in the Proposal Submission Tool (PST): After logging into NRAO Interactive Services, click on "Proposals" and then "New Proposal" on the top to the far right of the screen. Then Click on VLBA/HSA and "Create" (again on top to the far left). A proposal template will be created for you, click on the proposal number and this will open the proposal for you. There are seven screens to choose from and edit (there is an additional screen where you can find your disposition letter after the proposal has been reviewed).
    1. General: Title, abstract, proposal type, etc.. Edit this page by clicking on the "edit" button to top to the far right.
    2. Authors: List of authors and contact information. You can add an author by clicking on the "Add" button to the right on the page. Then search for your co-authors and if they are not in the database you can add them.
    3. Scientific Justification: Upload a pdf or txt of your scientific justification, no more than 4 pages in length (including figures, tables and references) with an 11pt font.
    4. Technical Justification: An important part of the proposal to be submitted is the Technical Justification.  Previously merely a required section in the Scientific Justification, it is now a separate element of each proposal.  Instead of the free format used in the Scientific Justification, we ask proposers to supply information on a number of standard topics, covering the wide range of technical issues of importance.  We have found that this reduces the likelihood that information is left out needed by the Technical Reviewers to judge the feasibility of the project as proposed. Follow the links in the form to obtain more information on the individual topics.  Click here to see an example.
    5. Sources: List of sources to observe. One slightly confusing thing here is that you have to create a "New Source Group" to add sources (button on upper right). After creating a group you can either add sources to it by hand or search for them with NED/SIMBAD. Adding sources to this section does not mean any time has been requested for them, they must be linked to a telescope resource in Sessions.
    6. Resources: Resources requested from the VLBA (antennas, frequencies, bit rates, correlator, etc.).  To add a resource click "add" on the right.  If proposing for the VLBA then the "Socorro-DiFX" correlator should be used. Set which telescope are being requested and the set the "Observing Parameters" and "Correlation Parameters" based on the scientific goals of the project. For most continuum experiments you will want the highest sustainable aggregate bit rate (currently 2 Gbps; see the relevant section of the OSS), i.e., the largest bandwidth and therefore the highest sensitivity.  For spectral line choose the number of baseband channels and their widths based on the expected frequency coverage of the lines, leaving some continuum on either side available for calibration.  If bandwidths narrower than 1 MHz are required, see the spectral resolution section of the OSS.
    7. Sessions: Describes the amount of time requested, and how it should be divided amongst the various sources and resources. Click on "New Session", this is where you actually request time on your sources at different frequencies.
  3. Examine and Submit: Go back to "My Proposals" and click on the printer (Print Proposal) icon next to the proposal code to see what the proposal will look like to a reviewer.  Once you are satisfied click the submit button (Submit Proposal) to submit the proposal.

Proposing for the VLBA

by Amy Mioduszewski last modified Apr 12, 2016 by Heidi Medlin
Call for Proposals Access to the call for proposals.
Proposal Preparation and Submission A brief description of the VLBA proposal process.
OSS The latest Observational Status Summary, a full description of the VLBA Instrumental Capabilities.  It also contains links to previous versions of the OSS.
The VLBA RSRO Program NRAO is now offering a program similar to the VLA's successful "Resident Shared Risk Observing" (RSRO) concept, to give users an opportunity to assist NRAO with VLBA development projects that would benefit from contributions by community experts.  In return, participating users would receive early access to the corresponding new capabilities.  Some areas of particular interest to NRAO, and details for proposing and participation in the RSRO program, are described on this page.
News to VLBA Observers Items of interest to the VLBA/HSA/VLBI Observing Community
Accurate Source Position Service NRAO offers to provide astrometric quality source positions in response to requests from users
Global VLBI The VLBA is a stand-alone VLBI array that is useful for addressing many scientific questions. However, in some cases, more sensitive telescopes, longer baselines, or additional high-frequency antennas are necessary to reach science goals

Observational Status Summary

by Gustaaf Van Moorsel last modified Jan 10, 2018

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The VLBA RSRO Program

by Jonathan Romney last modified Dec 18, 2017 by Walter Brisken

 

The VLBA Resident Shared Risk Observing (RSRO) program provides users with early access to new capabilities in exchange for a period of residency in Socorro to help commission those capabilities.  Proposals for any area of user interest are welcome; several desirable developments are listed below.  Details of participation in the VLBA RSRO program are provided in a following section.

Suggested RSRO Studies

"Y1" VLBI observing on the VLA. The phased-VLA capability is currently limited to a single subarray.  Thus, any VLBI observation either uses, or idles, each of the VLA's 27 antennas, which can only be justified when a large number are required for scientific success.  RSRO participants could contribute to extending the VLBI mode to a subarrayed configuration, to re-establish the "Y1" mode, with a single VLA antenna joining the VLBA.  That capability was valued in the pre-EVLA era for studies of intermediate-scale sources requiring baselines between the VLA's A configuration and the VLBA's shortest spacings.

Many pulse cal tones per channel.  The DiFX software correlator has the capability to extract every pulse cal tone in each channel (up to 128 in the most extreme case), compared to just two channels, which is the historical norm.  AIPS now has recent support for this in the form if increased capability of existing tasks and several new ones.  Many pulse cal tones may offer several new calibration or data assessment techniques.  Users seeking early use of this capability are invited to propose for a RSRO project with goals of validating the new software and developing/documenting best practices for its use.

DDC-4 capability at Arecibo.  All required hardware and most software required to use a DDC-4 observing mode is already available at Arecibo.  An RSRO participant with experience in using the Field System control software could assist in commissioning of the DDC-4 mode, and have early access to that capability.  In this case the residency would be at Arecibo, but remote assistance from VLBA personnel in Socorro would be available.

Rapid response capability. Dynamically scheduling the VLBA in response to a trigger should allow observing to begin within 5 to 10 minutes, in opportune situations.  Establishing a general rapid-response capability that would cover all conceivable cases is not considered feasible, so this RSRO program would allow the definition of triggers and responses suitable to a specific case of interest to the proposing user group.  The work required would include setting up software infrastructure and operations procedures for automated preemption of ongoing array activity, subject to prioritization constraints.

3mm VLBI with the LMT. New VLBI equipment has been installed at the Large Millimeter Telescope in Mexico, provided through a collaboration with MIT Haystack Observatory and the Smithsonian Astrophysical Observatory, enabling VLBI using their Redshift Search Receiver at 3mm.  Further commissioning will be needed to make this capability fully operational with the rest of the High Sensitivity Array.  RSRO participants are invited to assist with this effort.

 

Participation in the VLBA RSRO Program

The primary requirement of the RSRO program is that there be at least one expert from each participating group will to reside in Socorro and to contribute to commissioning, while incurring as little overhead from VLBA staff as possible. Limited support for accommodation in the NRAO Guest House for participants in the RSRO program may be available.

RSRO proposals should be submitted using the NRAO Proposal Submission Tool in response to a regular proposal call.  The proposal should include a scientific justification, as for normal proposals, which will be peer reviewed as part of NRAO's time allocation process.  Selecting "VLBA RSRO" from the "Observing Mode" menu on the Resources page makes an "RSRO Comments" text-entry facility available for describing the technical resources required.  A description of the personnel who will be involved in the residency along with their expertise and proposed dates of residency should also be included in the technical justification section.

    Acceptance of RSRO proposals will be based on both the outcome of the time allocation process and a review by NRAO staff to assess how the proposed capability and associated commissioning activities fit with VLBA priorities.

    In general, one week of resident commissioning effort is expected for every 20 hours of VLBA time awarded to an RSRO project, subject to negotiation. Ideally, residency should be at least 2 months, which is the minimum time useful to become familiar with technical aspects of the VLBA and to contribute effectively to commissioning. The period(s) of residency should in general occur in advance of the observing time awarded in order to commission the requested capabilities.

    It is possible for a member of the NRAO scientific staff to satisfy the residency requirement on an RSRO proposal.  NRAO staff considering providing the residency requirement for an RSRO proposal should consult with their supervisor for further information.  Graduate students will, in general, not satisfy the residency requirement, although there may be exceptional cases. Graduate students will be allowed to accompany their advisors as long as the advisor takes primary responsibility for managing the student's efforts. Resident personnel will work under NRAO management in order to optimize the overall commissioning effort. A set of deliverables will be agreed upon in advance of the start of the residency.

    The types of proposals considered under the RSRO program may include large (>200 hours) as well as normal projects. Qualified large projects proposed by consortia will be considered as long as the residency requirements are met. A single individual may satisfy the residency requirement for several small projects.

    We emphasize the "shared risk" nature of the RSRO program. Since observers will be attempting to use capabilities under development and in the process of being commissioned, NRAO can make no guarantee of the success of any observations made under this program, and no additional commitment is made beyond granting the hours actually assigned by the peer review process.

    VLBA and Global VLBI

    by Gustaaf Van Moorsel last modified Jan 04, 2016 by Claire Chandler

    VLBA TELESCOPE
    & GLOBAL VLBI

    [VLBI]

     

    • Instructions for Proposal Preparation and Submission

      • VLBA and HSA proposals, including VLBA+Effelsberg

        • VLBA and HSA proposals, including VLBA+Effelsberg proposals, must be prepared and submitted using the Proposal Submission Tool. See the HSA page for more detailed information.  Note that email submission of VLBA+Effelsberg proposals should no longer be used since these will in future be handled as a subset of the HSA.

        • Submission deadlines: February 1, August 1. A proposal must be received by close of business (5:00 p.m. = 1700 hours Eastern Standard or Daylight Time) on the date of the deadline. If the deadline falls on a holiday or weekend, it is extended to the next working day.

        • Submissions by email, fax, or paper will not be considered.

      • Global 3mm VLBI (GMVA)

        • GMVA projects are correlated at Bonn, using the DiFX software correlator.  GMVA proposals are submitted using the NRAO Proposal Submission Tool (PST).

        • Beginning semester 2016B phased ALMA may be requested as part of the GMVA.  See the most recent Call for Proposals for how to request inclusion of ALMA in the array.
        • Submission deadlines: February 1, August 1, as for VLBA/HSA, at 1700 Eastern Standard or Daylight Time.

      • EVN or Global cm VLBI

    • Information for visiting observers

    VLBA_FD.jpg

    by Amy Mioduszewski last modified Apr 25, 2011 by Purav Patel
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    Observing with the High Sensitivity Array

    by Amy Mioduszewski last modified Jun 21, 2017 by Walter Brisken

     

    Proposing and scheduling the HSA should be almost as easy as using the stand-alone VLBA, but there are some unavoidable complications that accompany the additional antennas. The purpose of this document is to alert the HSA user to these complications and suggest ways to deal with them.

    1. Instructions for doing VLBI at the non-VLBA telescopes:
    2. Proposals: Proposals should be sent to NRAO only, through the Proposal Submission Tool, which can be accessed via NRAO Interactive Services. Click on VLBA/HSA when creating the proposal.
    3. Scheduling: Use the Walker/NRAO SCHED software to make the observing schedule, available from anonymous ftp at: ftp.aoc.nrao.edu The SCHED manual has several example files to get you started. Please be sure to use the latest version of the software, or to run sched on the final schedule file submission.

      For scheduling note that:
      • Effelsberg has station name 'EB_VLBA'
      • Arecibo has station name 'ARECIBO'
      • GBT has station name 'GBT_VLBA'
      • The phased VLA has station name 'VLA27'
    4. Slew speeds:The Effelsberg, GBT, and Arecibo slew speeds are slower than for VLBA antennas. Be aware of this when writing your schedule, and be sure to examine the output from SCHED. SCHED has the latest information on slew speeds, including acceleration and deceleration, for all telescopes.
    5. Pointing:As the Effelsberg and GBT antenna beamwidth is ~4 times smaller than those of VLBA antennas, periodic pointing checks are essential, especially during short wavelength observations. Observers should leave frequent gaps in their VLBI schedules (~10 mins each) to allow the telescope operators to make these checks. They should be about every hour or two at 4cm, and more frequently at shorter wavelengths. See the VLBI on the GBT page for more specific information on how and when to schedule pointing checks.
      The VLA also requires pointing at frequencies lower than the VLBA, for the VLA however the pointing must be scheduled by the observer.  See VLBI @ the VLA:Scheduling Hints for more information.
    6. Submitting Schedules: The submission deadline is two weeks before the observation. The input file for SCHED, incorporating any non-standard setup files, should be e-mailed to vlbiobs@nrao.edu.  If you have problems submitting your schedule contact vlbiobs@nrao.edu If any changes are made to schedule after the deadline the the support personal at all the telescopes must be contacted.
    7. Frequencies: While the GBT has frequency coverage equal to the VLBA, changing receiver bands takes 10-15 minutes. For more details on changing frequencies at GBT see the VLBI on the GBT page.
      The VLA and VLBA have similar frequency bands, but the VLA receivers generally have a wider tuning range.
      See Instructions for Joint VLBA + Effelsberg Observing for information about frequency availability and changing between frequencies at Effelsberg.
      See Arecibo Observatory Receivers for information about frequencies at Arecibo.
    8. Non-Standard Frequency Setups: Observers using non-standard frequency set-up files (i.e. not one supplied with the current version of SCHED) should contact the the technical friends at the telescopes. These are Frank Ghigo at the GBT, Tapasi Ghosh at Arecibo, and Uwe Bach at Effelsberg. Contact should be made well before the observations so that any special files needed for tuning can be made in good time.
    9. Correlator: All observations will be correlated at the VLBA correlator in Socorro.
    10. Archive: All observations will be archived on-line and password protected during the 1 year proprietary period. Request a project access key from the data analysts. See the NRAO archive policy for further details.

      hsa_sample.key

      by Amy Mioduszewski last modified Apr 25, 2011 by Pat Murphy

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      News for VLBA/HSA/VLBI Proposers and Observers

      by Amy Mioduszewski last modified Sep 16, 2016 by Jonathan Romney
      Contributors: jromney

      September 16, 2016    —  J. D. Romney

      RDBE Delay and Phase Jumps

      Delay and phase jumps have been detected in observations made using both the DDC and PFB personalities of the RDBE. These occur only quite infrequently (as far as we are aware, at least), and characteristics of the jumps vary substantially, so it has not been possible to describe all the effects in detail, nor to recommend countermeasures beyond careful analysis of observational delays. General descriptions of the most common effects are sketched below.

      1> Delay jumps upon resumption of an observation following interruption for short USNO operations at PT, MK, and possibly other stations:  Any restart of an observation may require a reload of the appropriate FPGA firmware, and a resynchronization of the internal timekeeping may occur. A general rule for these cases is that return to delay and phase cannot be guaranteed on a schedule resumption, and comparison of delays at the affected stations before and after the interruption is necessary. Notification of the interruption has been included in the VLBA operators' logs for a long time, and was augmented recently to advise such a check.

      2> DDC delay jumps: Such jumps have been seen sporadically for the last ~2 years, and have been the focus of a major investigation, and of numerous attempted corrections in the DDC firmware, all without complete success to this point. In some but not all cases, such jumps occur (if at all) on the second use of any given setup in the observation schedule, and do not recur subsequently within the same schedule. This effect, and the overall low rate of occurrence, both limit efficient analysis.  Some test schemes have been developed to gather more data than available previously (at the cost of substantial observing time). Tests suggest a basic jump quantum that is inversely proportional to the channel bandwidth: 256ns / BW[MHz] for 2<=BW<=16;  jumps of this type are not known to occur for BW=1 nor BW>=32.  Some cases have been seen with small-integer multiples of that jump quantum.  A major rewrite of the DDC FPGA firmware is currently under way, aimed both at preventing such jumps, and at facilitating tests to verify error-free performance.

      3> PFB phase jumps: These have been rare enough to be thought not to occur any more, but at least one event was seen recently. The jump occurred only in the phase-cal results at one station, and was not seen in the actual interferometer phases.

      September 10, 2015

      RDBE_based VLBA Gains

      VLBA pointing and gain measurements in the past in the past have been made based on power levels detected by the legacy Baseband Converters (BBCs). Since February 2014, power levels have also been measured in the new RDBE broadband system. The analysis which produces the gain values given in the vlba_gains.key has been run in parallel with both data sets.  Until late August 2015, the vlba_gains.key derived from the BBCs was the one placed on the ftp site and used as the sources of the values distributed with exported data sets in the gain table.  On September 2, 2015 we switched to using the gains derived from the RDBE data in the vlba_gains.key file. For more information, go here.

      January 2, 2015

      2015B Call for Proposals Announced

      The 2015B Call for Proposals was announced on January 2, 2015.  Proposal deadline is February 2, 2015 at 17:00 Eastern Daylight Time (21:00 UTC).

      July 7, 2014

      2015A Call for Proposals Announced

      The 2015A Call for Proposals was announced on July 7, 2014.  Proposal deadline is August 1, 2014 at 17:00 Eastern Daylight Time (21:00 UTC).

      January 5, 2014

      2014B Call for Proposals Announced

      The 2014B Call for Proposals was announced on January 5, 2014.  Proposal deadline is February 3, 2014 at 17:00 Eastern Daylight Time (21:00 UTC).

      July 8, 2013

      2014A Call for Proposals Announced

      The 2014A Call for Proposals was announced on July 8, 2013.  Proposal deadline is August 1, 2013 at 17:00 Eastern Daylight Time (21:00 UTC).

      January 3, 2013

      2013B Call for Proposals Announced

      The 2013B Call for Proposals was announced on January 3, 2013.  Proposal deadline is February 1, 2013 at 17:00 Eastern Standard Time (22:00 UTC)..

      December 31, 2011

      VLBA flag problems (Nov 10 to Dec 22)

      During the second week of November, upgrades were made at Pie Town in support of the upgraded C-band receiver. These changes have transferred monitor and control of some antenna electronics from the "legacy" station computer to the modern system which is based on EVLA software. This new system is working well, however the legacy system, which is still responsible for generating flags for the station, was perpetually flagging data based on monitor points that no longer exist. The Hancock antenna C-band system was upgraded in December with the same issue beginning with observations made on Dec 10.

      Data observed after Nov 10 and correlated before Dec 7 will have a single erroneous flag for Pie Town encompassing the entire observation. Data observed between Dec 7 and Dec 22 won't have any flags for Pie Town or Hancock. Data observed after Dec 22 should be back to normal.

      VLBA operations staff have regenerated flag data for the Nov 10 through Dec 22 period. Users wishing to restore proper flags can follow the instructions to download cal.vlba.gz and then follow instructions in the AIPS Cookbook. The section titled Automatic formatting of VLBA and VLBA-like log files will explain how to use VLOG and UVFLG to load flags from the downloaded file. You may want to make a backup (with TASAV) of the original FL table before deleting it (with EXTD) just in case you want to go back to the original flags.

      Questions regarding the flagging problem and its corrections should be directed at the NRAO helpdesk.


      August 29, 2011

      Hancock VLBA station temporarily shut down by hurricane Irene

      The Hancock VLBA station was put into shutdown mode in the morning of August 27 in anticipation of high winds, heavy rains and power loss due to hurricane Irene.  Commercial power was lost at approximately 3 am Sunday morning and has not yet been restored.  The site techs were able to reach the station on Monday, August 29 and determined that there is no obvious damage to the antenna or structures.  Numerous trees are down around the site and on the roads and power lines have been downed by fallen trees.  It may take several days before power is restored, however, backup generators for critical systems (maser, cryogenics, etc.) are working so we anticipate a smooth return to operations once power is restored.


      August 8, 2011

      Error found in EOP corrections in AIPS

      Versions of the AIPS task CLCOR released between Sept. 21, 2009 and Aug. 4, 2011 used the wrong sign on the station Y coordinate when calculating Earth Orientation Parameter (EOP) corrections. The main adverse impact will be on phase referencing projects for which sufficiently large EOP corrections were made that the difference in the relative correction between calibrator and target is significant.  For more details click here.


      July 6, 2011

      Los Alamos antenna back in operation

      In the evening of July 6, 2011 the danger posed by the Las Conchas fire had subsided sufficiently that the Los Alamos VLBA antenna was put back in operation.  It has been taking part in VLBA observations since.


      July 2, 2011

      Las Conchas Fire near Los Alamos

      The Las Conchas Fire that started on June 26, 2011, came within a few miles of the LA VLBA antenna. The LA station is out of danger, but the fire continues to burn and is not yet contained. The Los Alamos National Laboratory remains closed. NRAO therefore has no access to the antenna at this time, and LA cannot currently be included in VLBA observations.


      June 30, 2011

      Call for proposals for semester 2012A

      The June 30, 2011 NRAO eNews contains the Call for Proposals for the GBT, EVLA, and VLBA/HSA/VLBI, along with general news for proposers.


      January 7, 2011

      Call for proposals for semester 2011B

      The January 7, 2011 NRAO eNews contains the Call for Proposals for the GBT, EVLA, and VLBA/HSA/VLBI, along with general news for proposers.


      September 15, 2010

      Call for proposals for trimester 2011A

      The September 15, 2010 NRAO eNews contains the Call for Proposals for the GBT, EVLA, and VLBA/HSA/VLBI, along with general news for proposers.


      June 21, 2010

      VLBA Pie Town azimuth track fixed

      The Pie Town VLBA antenna was restored to full service on June 17, 2010, after antenna mechanics were able to effect a repair to the split in the rail. The damaged rail section was regrouted and the split rail was welded. It is believed that the split in the rail was caused by a poor quality weld of the rail to the mounting plate during the construction of PT. It appears that this weld cracked during cooling and then slowly propagated up the rail until the failure occurred.


      June 1, 2010

      VLBA Pie Town antenna down for repair of azimuth track

      During a routine inspection of the Pie Town VLBA azimuth track on May 25, 2010, a split in the rail and grouting near bolt 20 was discovered. Until a repair is completed, the PT antenna will be unavailable for observing. Several options for the repair are under consideration, but PT will be out of service until at least July 1, 2010.


      May 14, 2010

      Call for proposals for trimester 2010C

      The May 14, 2010 NRAO eNews contains the Call for Proposals for the GBT, EVLA, and VLBA/HSA/VLBI, along with general news for proposers.

      VLA.jpg

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      High Sensitivity Array

      by Amy Mioduszewski last modified Nov 30, 2016 by Jonathan Romney

      By adding the GBT, phased VLA, Arecibo, and/or Effelsberg to a VLBA experiment the sensitivity can be increased by an order of magnitude. This capability opens up new avenues for scientific discovery. The aim of the High Sensitivity Array initiative is to facilitate the planning, scheduling, and calibration of observations making use of this array.

      Technical Information

        • Use the EVN sensitivity Calculator to estimate the rms noise.
        • Arecibo: Keep in mind the limitations on transit time for Arecibo of 1-2.75 hours for 0 < declination < 37 degrees (see also The VLBI Guide at Arecibo and The New Users Guide at Arecibo).
        • Effelsberg: Effelsberg has often been used in conjunction with the VLBA, and is frequency agile at 5 GHz and above. For more information about including Effelsberg with the HSA we refer to the Effelsberg HSA page.
        • Green Bank Telescope: The Green Bank Telescope is also commonly used with the VLBA, and is frequency agile (with some limitations) at all its bands.  See the VLBI at the GBT page for more information.
        • Very Large Array:  The Very Large Array (VLA) in only available in phased-array mode.  Please see the VLBI at the VLA page for further considerations.
        • Before you schedule your run consult Observing with the HSA.

       

      Follow these links to the HSA Telescopes:
      Link to GBT Link to Arecibo Link to VLA Link to VLBA Link to VLBA

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      Details of CLCOR/EOP Error

      by Amy Mioduszewski last modified Aug 18, 2011
      Versions of the AIPS task CLCOR released between Sept. 21, 2009 and Aug. 4, 2011 used the wrong sign on the station Y coordinate when calculating Earth Orientation Parameter (EOP) corrections. The main adverse impact will be on phase referencing projects for which sufficiently large EOP corrections were made that the difference in the relative correction between calibrator and target is significant.

      Details:

      An error has been found in the Earth Orientation Parameter (EOP)  corrections done by versions of CLCOR released after Sept. 21, 2009  but before Aug. 4, 2011.  In 2009, AIPS was changed to use a right  handed coordinate system for all arrays.  Prior to that time, VLBI  data sets used a left handed coordinate system in AIPS for historical  reasons.  Since 2009, the routine that reads the antenna tables can tell which system is in use because it recognizes a large number of antenna names and knows what the sign of station coordinate Y should be, which is the only difference between the systems.  If it finds a left handed system is in use, it changes the sign of all of the Y values to make it right handed.  Then other AIPS routines assume a right handed system.  All tasks that had code for dealing with left handed VLBI coordinates were changed when this behavior was installed. Unfortunately the EOP correction code in CLCOR was overlooked, and the change of the sign of Y for VLBI data sets was inadvertently left in place.

      To test that the current corrections are correct, we recently correlated a few scans of a normal VLBI project with EOP values that were set very far from the correct values.  We then used CLCOR to correct the data.  The correlator output from this test, with no corrections, shows much higher fringe rates than normal.  When the EOP are corrected with the CLCOR containing the error, the residual fringe rates got even higher, clearly showing that the correction was not being done properly.  When the latest CLCOR, as released on Aug 4, 2011, was used, the residual rates returned to small values.  The phase differences on a strong source between the data with the "good" corrections and the data from the normal processing run, done with the same "correct" EOP values used in the test, were under a few degrees, and less than the scatter, on all but 3 stations.  For the outer stations (MK, SC, HN), the offsets were 20 to 30 degrees and, curiously, all of the same sign.

      We are still trying to understand the phase offsets on the outer stations.  But the EOP corrections involved in the test (0.02s in UT1-UTC and 0.2 arcseconds in X and Y) were far larger than anything expected to be seen in real observations.  So for real cases, we expect any such differences to be very small.  In the interests of getting this message to our users quickly, we are not waiting until we fully understand those remaining differences.

      The data processing sequence recommended for all projects in the AIPS Cookbook includes making EOP corrections in Step 9.  This is normally done using the procedure VLBAEOPS.  It can also be done by running CLCOR directly and requesting OPTYPE='EOPS'.  The reason for making these corrections was originally that there was a period of a few months when the correlator was using poor values.  But regardless, the correlator has to use values determined before the data are correlated, which is before the final, best values are obtained by the geodetic groups.  For CLCOR, a file with the most current values provided by the USNO is downloaded and used to make a differential correction to what was used on the correlator.  Unfortunately, for the last 2 years, this step has had the effect of degrading the data.

      The magnitude of the issue depends on how much change there was in the EOP values between those used for correlation and those used by CLCOR. For the large majority of projects, those changes will be small. Roughly, a change in UT1-UTC has an effect about like a source position error of that amount in the RA.  Changes in X and Y are also about like source position changes.  The harm that can be caused is mainly the result of the differential correction on source and calibrator for phase reference operations, such as for weak source detection or for astrometry.  For calibrator data, or for self calibration imaging, the errors in the correction will be removed by fringe fitting or self calibration and so it is not a concern.  The magnitude of the harmful effect for phase referencing will be reduced by the calibrator-target separation in radians.  In cases where the corrections were small, or the separation is small, the error may not have a significant impact.

      To determine whether a particular data set is adversely affected, it might be best to rerun the EOP correction to see how big a difference the corrected code makes.  Usually the EOP correction is run early in the processing sequence, although possibly after the ionospheric correction.  The CL tables at this stage are pretty simple so changes should be easy to see.  First check that there is any difference. There won't be (other than due to small changes in the current EOP tables vs those used in the original processing) if the most recent CLCOR was used or, more likely, if a version from before Sept. 21, 2009 was used on a data set with left handed coordinates.  If that is the case, there is no further concern.  If there are differences, you will have to decide if they are large enough to affect the final scientific results.  The main concern is the differential differences between calibrator and target scans for phase referencing.  Those differences should be checked by examining the CL tables carefully. Often the EOP used on the correlator will be good enough that the corrections made by CLCOR will be small enough to ignore.  But there may well be a few projects for which that is not true.  If you are unlucky and one of those is yours, you will need to redo all the processing that affects phases that was done after the EOP corrections were applied.  Data editing, polarization calibration, and calibrator imaging should be ok.  But fringe fitting, final self calibration on calibrators, and phase transfer to the target will need to be redone.

      To obtain the corrected version of CLCOR, run the AIPS midnight job on either TST (31DEC11) or NEW (31DEC10 - there has been a patch).

      If you have questions, please use the VLBA help desk and submit a ticket to the VLBA or to AIPS.

      We apologize for any inconvenience created by this issue.

      Since the above message was distributed to the VLBI and VLBA_USERS email lists, Andreas Brunthaler wrote a script that compares the EOP values used in the correlation jobs with the latest values from the USNO.  He has run that script on all of the projects in our archive of correlation job scripts.  He is providing those results for the following years: 2006, 2007, 2008, 2009, 2010, 2011 (though Aug 17).

      Those data show that most correlations were done with good EOP values, but there are some exceptions.

      Cheers,

      Craig Walker

      EOP difference 2006

      by Amy Mioduszewski last modified Aug 18, 2011
      Difference in EOPs from correlation and the best USNO numbers from all the experiments in 2006
        Obs     MJD    diff X   diff Y  diff UT1  combined
      [mas] [mas] [ms] [mas]
      ----------------------------------------------------
      bb191c 53766 -0.07 0.44 0.007 0.46
      bb200c 53752 -0.15 0.66 -0.005 0.68
      bb200d 53755 0.00 0.31 0.007 0.33
      bb218 53738 -0.06 0.34 0.006 0.36
      bc152l 53742 -0.06 0.35 0.013 0.41
      bc152m 53754 -0.15 0.49 0.014 0.55
      bc156b 53742 -0.06 0.35 0.013 0.41
      bc159 53759 -0.04 0.48 0.013 0.52
      bd105e 53738 -0.09 0.56 0.008 0.58
      bd105g 53765 -0.14 0.54 -0.007 0.57
      bd109c 53756 -0.05 0.35 0.009 0.38
      bd115 53743 -0.11 0.45 0.010 0.49
      bg161 53741 -0.06 0.34 0.015 0.41
      bk127b 53745 -0.05 0.27 0.017 0.37
      bk129b 53738 -0.09 0.56 0.008 0.58
      bl128ac 53757 -0.10 0.42 0.002 0.43
      bl128bc 53758 -0.13 0.47 -0.000 0.49
      bl128cc 53755 -0.13 0.56 0.021 0.66
      bl128cg 53744 -0.18 0.50 0.008 0.54
      bl138d 53755 -0.02 0.31 0.007 0.33
      bl139a 53757 -0.10 0.42 0.002 0.43
      bm229f 53748 -0.02 0.35 0.004 0.36
      bm230h 53739 -0.09 0.28 0.016 0.38
      bm230i 53764 -0.13 0.54 -0.013 0.59
      bm235c 53743 -0.11 0.45 0.010 0.49
      bm235d 53761 -0.03 0.36 0.020 0.47
      bm238b 53743 -0.11 0.45 0.010 0.49
      bn035 53766 -0.08 0.44 0.008 0.46
      bp124a 53758 -0.13 0.49 -0.000 0.51
      bp129 53745 -0.08 0.37 0.015 0.44
      br099i 53751 -0.16 0.64 -0.008 0.67
      br100dc 53749 -0.06 0.44 -0.005 0.45
      bt085a 53763 -0.12 0.45 -0.006 0.47
      bt085b 53764 -0.13 0.54 -0.013 0.59
      bt085l 53739 -0.08 0.49 0.021 0.59
      bb213c 53795 -0.12 0.49 -0.007 0.52
      bc152n 53771 -0.10 0.57 -0.004 0.58
      bc161a 53770 -0.17 0.59 0.000 0.61
      bd105h 53769 -0.08 0.72 0.012 0.75
      bd112a 53774 -0.09 0.58 0.019 0.65
      bd112b 53777 -0.10 0.48 -0.002 0.49
      bf088a 53789 -0.08 0.48 0.000 0.49
      bf088b 53794 -0.07 0.55 -0.003 0.56
      bh135c 53770 -0.17 0.47 -0.002 0.50
      bh135d 53773 -0.05 0.67 0.013 0.70
      bh136a 53776 -0.01 0.35 0.010 0.38
      bk130a 53781 -0.10 0.53 0.002 0.54
      bk130b 53783 -0.09 0.43 0.011 0.47
      bk130c 53790 -0.09 0.44 0.010 0.47
      bl128ed 53778 -0.09 0.52 -0.007 0.54
      bl137a 53779 -0.16 0.45 -0.002 0.48
      bm229g 53772 -0.04 0.50 -0.003 0.50
      bm232c 53791 -0.02 0.49 -0.001 0.49
      bm235e 53789 -0.08 0.48 -0.001 0.49
      bm249a 53795 -0.10 0.32 -0.003 0.34
      bo026 53793 -0.10 0.51 -0.003 0.52
      br100cc 53792 -0.03 0.52 -0.004 0.52
      bs161b 53780 -0.09 0.39 0.007 0.41
      bt085c 53776 -0.01 0.35 0.010 0.38
      bt085d 53792 -0.03 0.52 -0.004 0.52
      gc025a 53786 -0.14 0.47 -0.005 0.50
      bb184c 53821 -0.19 0.46 -0.015 0.55
      bb217b 53811 -0.00 0.46 -0.002 0.46
      bb221 53806 -0.17 0.51 -0.007 0.55
      bb222a 53818 -0.00 0.50 -0.020 0.58
      bb222b 53821 -0.19 0.46 -0.015 0.55
      bb222c 53820 -0.15 0.48 -0.015 0.55
      bb222d 53815 -0.06 0.37 -0.004 0.38
      bb222e 53822 -0.01 0.51 0.000 0.51
      bb222f 53818 -0.00 0.50 -0.020 0.58
      bb222h 53820 -0.15 0.48 -0.015 0.55
      bb222i 53825 -0.53 0.76 -0.003 0.93
      bc152o 53797 -0.04 0.34 0.006 0.35
      bc152p 53812 -0.19 0.44 -0.004 0.48
      bc152q 53825 -0.53 0.76 -0.003 0.93
      bc156c 53817 -0.15 0.51 -0.017 0.59
      bd108a 53805 -0.18 0.44 -0.007 0.49
      bf075c 53800 -0.21 0.54 -0.011 0.60
      bf075d 53815 -0.06 0.37 -0.004 0.38
      bg164c 53810 -0.18 0.45 -0.009 0.50
      bh139 53821 -0.19 0.46 -0.015 0.55
      bl128bd 53826 -0.64 0.76 -0.040 1.16
      bl128cd 53823 -0.20 0.61 0.007 0.65
      bl128dd 53819 -0.13 0.45 -0.011 0.50
      bl128fd 53796 -0.09 0.54 -0.012 0.58
      bl128gd 53810 -0.18 0.45 -0.009 0.50
      bl137b 53804 -0.05 0.44 0.003 0.45
      bm229h 53807 -0.17 0.44 -0.009 0.49
      bm230j 53800 -0.21 0.54 -0.011 0.60
      bm230k 53824 -0.49 0.68 0.011 0.85
      bm234b 53796 -0.07 0.47 -0.010 0.50
      bm235f 53812 -0.19 0.44 -0.004 0.48
      bm245a 53821 -0.19 0.46 -0.015 0.55
      bm245b 53825 -0.53 0.76 -0.003 0.93
      bm249b 53799 -0.18 0.46 -0.012 0.53
      bm249c 53801 -0.19 0.59 -0.009 0.63
      bm249d 53804 -0.05 0.44 0.003 0.45
      bo022d 53814 -0.17 0.49 -0.011 0.54
      bo022e 53811 -0.04 0.38 0.007 0.40
      bo022f 53799 -0.18 0.46 -0.012 0.53
      bo026b 53808 -0.05 0.43 0.003 0.44
      bp126 53820 -0.15 0.48 -0.015 0.55
      br100ac 53811 -0.04 0.38 0.007 0.40
      br100fb 53817 -0.15 0.51 -0.017 0.59
      br119a 53801 -0.19 0.59 -0.010 0.64
      bs150c 53808 -0.05 0.43 0.003 0.44
      bs167a 53800 -0.20 0.54 -0.010 0.60
      bs167b 53806 -0.17 0.51 -0.012 0.57
      bs167c 53813 -0.17 0.50 -0.008 0.54
      bs167d 53818 -0.00 0.50 -0.020 0.58
      bs167e 53824 -0.49 0.68 0.011 0.85
      bt085e 53814 -0.17 0.49 -0.011 0.54
      bv059ba 53798 -0.11 0.40 -0.002 0.42
      by021 53799 -0.18 0.49 0.007 0.53
      by021b 53819 -0.13 0.45 -0.011 0.50
      bb200g 53839 -0.10 0.55 -0.021 0.64
      bb200h 53846 -0.05 0.39 0.002 0.39
      bb220b 53834 -0.14 0.50 -0.019 0.59
      bb222g 53827 -0.70 0.60 -0.022 0.98
      bb223 53849 -0.20 0.42 -0.015 0.52
      bc152r 53839 -0.10 0.55 -0.021 0.64
      bc161b 53835 -0.15 0.57 -0.019 0.65
      bd114a 53848 -0.16 0.50 -0.026 0.65
      bg164a 53845 -0.16 0.43 -0.014 0.50
      bg164b 53854 -0.13 0.44 -0.008 0.47
      bh136b 53843 -0.14 0.55 -0.016 0.62
      bk114g 53855 -0.10 0.50 -0.025 0.63
      bk127c 53856 -0.14 0.50 -0.014 0.56
      bl128ad 53827 -0.70 0.60 -0.022 0.98
      bl128ee 53846 -0.04 0.42 0.000 0.42
      bl137c 53831 -0.17 0.41 -0.012 0.48
      bl137d 53854 -0.13 0.44 -0.008 0.47
      bl139b 53850 0.03 0.52 -0.025 0.64
      bm229i 53836 -0.08 0.47 -0.001 0.48
      bm230l 53847 -0.15 0.42 -0.012 0.48
      bm235g 53834 -0.14 0.50 -0.019 0.59
      bm241 53856 -0.14 0.50 -0.014 0.56
      bm244a 53835 -0.15 0.57 -0.019 0.65
      bm244b 53843 -0.14 0.55 -0.016 0.62
      bm244c 53849 -0.19 0.46 -0.026 0.63
      bm245c 53830 -1.44 0.52 0.260 4.19
      bo026c 53828 -1.01 0.47 0.042 1.28
      bo026d 53842 -0.16 0.48 -0.028 0.66
      bo027a 53851 -0.03 0.57 -0.030 0.73
      bp124b 53853 -0.04 0.41 0.002 0.41
      bp128a 53830 -1.44 0.52 0.260 4.19
      br100bb 53832 -0.10 0.41 0.002 0.42
      br100dd 53841 -0.20 0.47 -0.045 0.85
      br100eb 53833 -0.19 0.44 -0.012 0.51
      br106b 53842 -0.16 0.47 -0.017 0.56
      br119b 53845 -0.16 0.43 -0.014 0.50
      br122a 53840 -0.14 0.51 -0.040 0.80
      bs167f 53830 -1.44 0.52 0.260 4.19
      bt085f 53829 -1.18 0.65 0.155 2.69
      bt085g 53840 -0.14 0.52 -0.045 0.86
      bv059aa 53834 -0.14 0.50 -0.019 0.59
      bw082a 53834 -0.14 0.50 -0.019 0.59
      bw082b 53837 -0.22 0.48 -0.002 0.53
      bw082c 53840 -0.14 0.51 -0.040 0.80
      bw082d 53843 -0.14 0.55 -0.016 0.62
      bw082e 53846 -0.04 0.31 0.006 0.33
      ba078a 53875 -0.10 0.41 -0.007 0.43
      bb182b 53868 -0.07 0.47 -0.003 0.48
      bb219 53883 -0.10 0.49 -0.014 0.54
      bb222j 53866 -0.12 0.48 -0.011 0.52
      bb222k 53876 -0.10 0.46 -0.023 0.58
      bb222l 53877 -0.14 0.50 -0.020 0.60
      bc142b 53887 -0.16 0.50 -0.013 0.56
      bc161c 53884 -0.11 0.51 -0.009 0.54
      bf089 53880 -0.14 0.46 -0.009 0.50
      bh135e 53866 -0.12 0.48 -0.011 0.52
      bl137e 53880 -0.14 0.46 -0.009 0.50
      bm229j 53860 -0.13 0.50 -0.004 0.52
      bm230m 53872 -0.20 0.44 -0.005 0.49
      bm235h 53864 -0.07 0.39 0.008 0.41
      bm235i 53887 -0.16 0.50 -0.013 0.56
      bo027b 53859 -0.16 0.53 -0.017 0.61
      bo027c 53865 -0.19 0.45 0.003 0.49
      bo027d 53872 -0.20 0.44 -0.005 0.49
      bo027e 53879 -0.16 0.52 -0.007 0.55
      bo027f 53885 -0.13 0.50 -0.006 0.52
      bp128b 53878 0.01 0.57 -0.018 0.63
      bp130 53881 -0.03 0.50 -0.035 0.73
      br100cd 53882 -0.10 0.49 -0.021 0.59
      bs150d 53868 -0.07 0.47 -0.003 0.48
      bs158b 53869 -0.15 0.47 -0.008 0.51
      bs158c 53886 -0.11 0.53 -0.019 0.61
      bt085h 53857 -0.17 0.53 -0.010 0.58
      bt085i 53870 -0.14 0.45 -0.005 0.48
      bt085j 53887 -0.16 0.50 -0.013 0.56
      bt085m 53883 -0.10 0.49 -0.012 0.53
      bw082f 53869 -0.16 0.47 -0.009 0.51
      by021c 53871 -0.31 0.60 0.040 0.90
      ba080a 53909 -0.01 0.54 -0.010 0.56
      bb225a 53897 -0.12 0.48 -0.013 0.53
      bc160 53912 -0.03 0.50 -0.012 0.53
      bd117a 53917 -0.05 0.47 -0.015 0.52
      bf075e 53910 -0.05 0.48 -0.024 0.60
      bf075f 53913 -0.05 0.48 -0.002 0.48
      bf090 53916 -0.02 0.40 -0.006 0.41
      bg166 53902 -0.09 0.57 -0.007 0.59
      bh135f 53917 -0.05 0.47 -0.015 0.52
      bh136d 53911 -0.05 0.48 -0.021 0.58
      bh142 53889 -0.14 0.35 -0.003 0.38
      bk131a 53896 -0.14 0.51 -0.012 0.56
      bk131b 53905 -0.06 0.49 -0.037 0.74
      bk131c 53895 -0.06 0.58 -0.013 0.61
      bl128ae 53899 0.04 0.47 -0.022 0.58
      bl128be 53897 -0.12 0.48 -0.014 0.54
      bl128ce 53891 -0.13 0.46 0.004 0.48
      bl128de 53888 -0.08 0.64 -0.022 0.72
      bl128ef 53912 -0.03 0.50 -0.012 0.53
      bl128ge 53890 -0.12 0.43 0.011 0.48
      bl137f 53902 -0.09 0.57 -0.009 0.59
      bl142a 53908 -0.04 0.55 -0.009 0.57
      bm235j 53909 -0.02 0.54 -0.008 0.55
      bm244d 53915 -0.09 0.71 0.010 0.73
      bm244e 53916 -0.02 0.40 -0.006 0.41
      bm244f 53917 -0.04 0.47 -0.025 0.60
      bm247a 53904 -0.06 0.52 -0.042 0.82
      bm248a 53908 -0.04 0.55 -0.009 0.57
      bp125a 53891 -0.13 0.47 0.003 0.49
      bp125b 53898 -0.15 0.50 -0.008 0.54
      bp128c 53910 -0.05 0.48 -0.024 0.60
      br122b 53895 -0.06 0.58 -0.013 0.61
      bs158d 53900 -0.06 0.44 -0.024 0.57
      bs166a 53898 -0.15 0.50 -0.008 0.54
      bt085k 53906 0.08 0.49 -0.020 0.58
      bu031a 53911 -0.05 0.48 -0.021 0.58
      bv059bb 53889 -0.13 0.50 -0.003 0.52
      gb058 53903 -0.05 0.34 -0.012 0.39
      ba082a 53933 -0.04 0.48 -0.021 0.58
      bb226 53918 -0.08 0.53 -0.022 0.63
      bb235 53934 -0.11 0.47 -0.014 0.53
      bc157a 53943 -0.01 0.51 -0.013 0.55
      bd114b 53945 0.00 0.47 -0.012 0.50
      bd117b 53920 -0.07 0.50 -0.008 0.52
      bd117c 53924 -0.07 0.41 -0.009 0.44
      bd117d 53928 -0.02 0.51 -0.004 0.51
      bd117e 53932 -0.06 0.51 -0.035 0.73
      bd117f 53935 -0.06 0.52 -0.013 0.56
      bd117g 53938 -0.05 0.51 -0.020 0.59
      bd117h 53941 -0.10 0.49 -0.033 0.70
      bd117i 53944 -0.06 0.42 0.007 0.44
      bd117j 53947 -0.07 0.47 -0.017 0.54
      be048 53928 -0.02 0.51 -0.004 0.51
      bg167 53918 -0.08 0.53 -0.022 0.63
      bh135g 53920 -0.07 0.50 -0.008 0.52
      bh135h 53929 -0.01 0.45 -0.011 0.48
      bl122c 53926 -0.03 0.50 -0.021 0.59
      bl137g 53924 -0.07 0.41 -0.018 0.50
      bl139c 53931 -0.05 0.46 -0.014 0.51
      bl142b 53931 -0.05 0.46 -0.014 0.51
      bm227b 53926 -0.03 0.50 -0.021 0.59
      bm248b 53935 -0.06 0.46 0.005 0.47
      bo025a 53939 -0.05 0.54 -0.018 0.61
      bo025b 53943 -0.01 0.50 -0.012 0.53
      bo025c 53946 -0.03 0.47 -0.033 0.68
      bo025d 53945 0.00 0.47 -0.013 0.51
      bo025e 53938 -0.05 0.51 -0.021 0.60
      br100de 53940 -0.07 0.52 -0.017 0.58
      bs160a 53933 -0.04 0.48 -0.022 0.58
      bt085n 53934 -0.11 0.47 -0.012 0.52
      bt085o 53948 -0.06 0.50 -0.028 0.66
      bu031b 53932 -0.06 0.51 -0.035 0.73
      bu031c 53947 -0.07 0.47 -0.017 0.54
      bv059ab 53924 -0.07 0.41 -0.018 0.50
      bw082g 53931 -0.09 0.48 -0.023 0.60
      bb200e 53960 -0.06 0.51 -0.038 0.77
      bb200i 53950 -0.08 0.55 -0.034 0.75
      bd116 53952 -0.08 0.47 -0.023 0.59
      be049 53960 -0.06 0.51 -0.038 0.77
      bf088c 53977 -0.10 0.49 -0.038 0.76
      bg165 53966 -0.09 0.52 -0.028 0.67
      bj045d 53974 -0.11 0.54 -0.027 0.68
      bj045h 53973 -0.06 0.51 -0.015 0.56
      bj050b 53973 -0.06 0.52 -0.016 0.58
      bk127d 53961 -0.07 0.51 -0.028 0.66
      bl128cf 53971 -0.06 0.47 -0.024 0.60
      bl128df 53975 -0.10 0.55 -0.024 0.66
      bl128gf 53970 -0.07 0.49 -0.024 0.61
      bl137h 53957 -0.13 0.52 -0.018 0.60
      bl143a 53973 -0.07 0.49 -0.016 0.55
      bm235k 53952 -0.08 0.47 -0.023 0.59
      bm247b 53958 -0.09 0.41 0.004 0.42
      bo025f 53965 -0.06 0.46 -0.019 0.54
      bp128d 53955 -0.05 0.45 -0.033 0.67
      bt085p 53951 -0.17 0.40 -0.037 0.70
      bt085q 53953 -0.06 0.51 -0.025 0.64
      bt085r 53955 -0.05 0.45 -0.033 0.67
      bt085s 53960 -0.06 0.51 -0.038 0.77
      bu031d 53954 -0.08 0.50 -0.028 0.66
      bw086a 53951 -0.17 0.40 -0.037 0.70
      ba080b 53982 -0.07 0.55 -0.062 1.08
      bb213d 53983 -0.06 0.47 -0.037 0.73
      bb225b 54000 -0.16 0.44 -0.003 0.47
      bc157b 54007 -0.10 0.42 0.002 0.43
      bc161d 53995 -0.10 0.52 -0.031 0.70
      bf091 53994 -0.09 0.48 -0.017 0.55
      bh136e 53999 -0.11 0.50 -0.015 0.56
      bh145a 53995 -0.10 0.52 -0.031 0.70
      bi033a 53993 0.01 0.51 -0.024 0.62
      bj045f 53989 -0.06 0.53 -0.025 0.65
      bj045g 54004 0.01 0.49 -0.011 0.52
      bj045i 54001 -0.06 0.31 -0.006 0.33
      bl128af 53984 -0.05 0.50 0.003 0.50
      bl128bf 53987 -0.09 0.48 -0.022 0.59
      bl137i 53985 -0.07 0.53 -0.018 0.60
      bl143b 53994 -0.05 0.51 -0.026 0.64
      bm234c 53988 -0.07 0.51 -0.029 0.67
      bm235l 53981 -0.08 0.52 -0.051 0.93
      bm244g 53997 -0.07 0.57 -0.012 0.60
      bm244h 54001 -0.10 0.45 -0.015 0.51
      bm244i 54007 -0.10 0.42 0.002 0.43
      bm247c 53986 -0.11 0.50 -0.014 0.55
      bp128e 54005 -0.06 0.49 -0.011 0.52
      bp131a 53990 -0.06 0.48 -0.004 0.49
      br100ce 53980 -0.09 0.50 -0.028 0.66
      br100fc 54008 -0.10 0.42 -0.011 0.46
      br106c 54008 -0.10 0.42 -0.011 0.46
      br121a 53983 -0.06 0.47 -0.038 0.74
      br121b 54002 -0.08 0.49 -0.026 0.63
      bs150e 54000 -0.15 0.48 -0.006 0.51
      bs158a 54003 -0.07 0.50 -0.013 0.54
      bs162a 53997 -0.07 0.57 -0.014 0.61
      bs162b 53996 -0.08 0.57 -0.027 0.70
      bs169a 54009 -0.13 0.47 -0.012 0.52
      bt088a 53998 -0.11 0.50 0.012 0.54
      bu031e 53995 -0.10 0.52 -0.031 0.70
      bu031f 54009 -0.08 0.39 -0.012 0.44
      bv059bc 53992 -0.04 0.50 -0.019 0.58
      be044a 54024 -0.07 0.53 -0.014 0.57
      be044b 54025 -0.12 0.53 -0.022 0.64
      be044d 54026 -0.08 0.51 -0.016 0.57
      be044e 54031 -0.05 0.48 -0.014 0.53
      be044f 54036 -0.08 0.48 -0.018 0.56
      be044h 54034 -0.09 0.41 -0.014 0.47
      be047 54039 -0.09 0.55 -0.016 0.61
      bj061a 54020 -0.06 0.30 -0.010 0.34
      bk132 54029 -0.08 0.46 -0.014 0.51
      bl137j 54015 -0.07 0.51 -0.013 0.55
      bl139d 54010 -0.09 0.50 -0.013 0.54
      bm247d 54014 -0.05 0.43 -0.024 0.56
      bm248c 54020 -0.09 0.48 -0.012 0.52
      bp125c 54029 -0.08 0.46 -0.014 0.51
      bp136a 54034 -0.09 0.41 -0.014 0.47
      bp136b 54035 -0.07 0.46 -0.039 0.75
      br100ad 54013 -0.07 0.49 -0.004 0.50
      br100bc 54013 -0.07 0.49 -0.004 0.50
      br100df 54028 -0.12 0.32 -0.007 0.36
      br100ec 54016 -0.06 0.48 -0.012 0.52
      br121c 54018 -0.11 0.45 -0.015 0.52
      br121d 54033 -0.09 0.42 -0.014 0.48
      bs170a 54017 -0.07 0.51 -0.015 0.56
      bs170b 54024 -0.07 0.53 -0.014 0.57
      bt087b 54023 -0.08 0.42 -0.011 0.46
      bw086b 54011 -0.15 0.42 -0.007 0.46
      bz034a 54034 -0.10 0.41 -0.011 0.45
      bz034b 54035 -0.07 0.46 -0.039 0.75
      bz034c 54036 -0.08 0.48 -0.018 0.56
      bz034d 54037 -0.09 0.52 -0.014 0.57
      bz034e 54038 -0.12 0.51 -0.006 0.53
      bz034f 54039 -0.09 0.55 -0.016 0.61
      bz034g 54040 -0.07 0.51 -0.017 0.57
      ba078b 54063 -0.17 0.47 -0.018 0.57
      ba082b 54056 -0.15 0.40 -0.010 0.45
      bb230a 54070 -0.12 0.46 -0.007 0.49
      bc167a 54051 -0.14 0.43 -0.012 0.49
      bd114c 54046 -0.12 0.53 -0.019 0.61
      be044g 54041 -0.08 0.52 -0.008 0.54
      be044i 54060 -0.13 0.43 -0.024 0.58
      bh136f 54069 -0.10 0.45 -0.017 0.53
      bi033b 54049 -0.06 0.35 -0.005 0.36
      bl137k 54050 -0.15 0.39 -0.012 0.45
      bl147a 54048 -0.10 0.35 -0.032 0.60
      bl147b 54043 -0.11 0.43 -0.012 0.48
      bm132b 54059 -0.12 0.46 -0.014 0.52
      bm239a 54041 -0.08 0.52 -0.008 0.54
      bm239b 54066 -0.13 0.44 -0.016 0.52
      bm248d 54057 -0.15 0.42 -0.012 0.48
      bm251 54042 -0.09 0.41 -0.016 0.48
      bm252a 54046 -0.13 0.52 -0.018 0.60
      bm252b 54053 -0.15 0.44 -0.015 0.52
      bp128f 54067 -0.16 0.36 -0.014 0.45
      bp131b 54058 -0.12 0.43 -0.015 0.50
      bp134a 54069 -0.10 0.45 -0.017 0.53
      bp138 54048 0.00 0.26 -0.032 0.55
      bs169b 54043 -0.11 0.43 -0.012 0.48
      bs169c 54043 -0.11 0.43 -0.012 0.48
      bt088b 54044 -0.13 0.44 -0.014 0.50
      bt088c 54062 -0.12 0.41 -0.013 0.47
      bv059ac 54065 -0.15 0.45 -0.017 0.54
      bw077b 54057 -0.15 0.42 -0.012 0.48
      ba080c 54073 -0.12 0.48 -0.018 0.56
      bb209c 54073 -0.12 0.48 -0.018 0.56
      bb225c 54084 -0.27 0.42 -0.020 0.58
      bb227a 54080 -0.14 0.51 -0.032 0.71
      bb228a 54073 -0.12 0.48 -0.017 0.56
      bb228b 54081 -0.17 0.44 -0.002 0.47
      bb231a 54093 -0.10 0.38 -0.015 0.45
      bb231b 54097 -0.22 0.38 -0.007 0.45
      bb231c 54099 -0.20 0.47 -0.007 0.52
      bb231d 54100 -0.20 0.46 -0.017 0.56
      bb233a 54081 -0.14 0.33 0.003 0.36
      bb234 54092 -0.16 0.41 -0.011 0.47
      bl128ff 54092 -0.05 0.31 -0.011 0.35
      bl128fg 54090 -0.07 0.32 -0.009 0.35
      bl137l 54071 -0.10 0.48 -0.011 0.52
      bl147c 54090 -0.07 0.32 -0.009 0.35
      bm247e 54087 -0.15 0.47 -0.023 0.60
      bm253a 54079 -0.14 0.46 -0.039 0.76
      bp133a 54088 -0.17 0.50 -0.032 0.71
      bs150f 54076 -0.17 0.43 -0.010 0.49
      bs160b 54085 -0.20 0.45 -0.014 0.54
      bw086c 54074 -0.20 0.50 -0.016 0.59
      gc028b 54098 -0.14 0.53 0.006 0.56
      ----------------------------------------------------
      Maximum difference between used and final EOPs:
      XPOLE: 1.44 mas; YPOLE: 0.76 mas; UT1-UTC: 0.260000000004 milliseconds; combined: 4.19 mas.

      From 416 projects, 201 (86) have differences larger than 0.10 (0.15) mas in XPOLE.
      From 416 projects, 416 (416) have differences larger than 0.10 (0.15) mas in YPOLE.
      From 416 projects, 272 (42) have differences larger than 10 (30) microseconds in UT1-UTC.

      EOP difference 2007

      by Amy Mioduszewski last modified Aug 18, 2011
      Difference in EOPs from correlation and the best USNO numbers from all the experiments in 2007.
        Obs     MJD    diff X   diff Y  diff UT1  combined
      [mas] [mas] [ms] [mas]
      ----------------------------------------------------
      bb200f 54108 -0.06 0.39 -0.006 0.40
      bb200j 54116 -0.04 0.48 0.032 0.68
      bb229a 54127 -0.04 0.41 -0.012 0.45
      bb229b 54129 -0.04 0.39 -0.013 0.44
      bb232a 54130 -0.05 0.40 -0.031 0.62
      bc157c 54105 -0.12 0.48 0.009 0.51
      bc167b 54131 -0.07 0.34 -0.030 0.57
      be044c 54128 -0.02 0.37 -0.017 0.45
      bg169a 54132 -0.04 0.35 -0.029 0.56
      bg169c 54125 -0.09 0.30 -0.010 0.35
      bj045j 54118 -0.06 0.36 -0.007 0.38
      bl137r 54106 -0.16 0.47 -0.009 0.51
      bm239c 54109 -0.05 0.38 0.014 0.44
      bm244j 54105 -0.12 0.48 0.010 0.52
      bm244k 54118 -0.06 0.36 -0.007 0.38
      bm244l 54119 -0.09 0.35 0.011 0.40
      bo028 54114 -0.09 0.41 -0.018 0.50
      bp133b 54112 -0.04 0.38 0.031 0.60
      br120a 54115 -0.07 0.39 0.005 0.40
      bt087c 54104 -0.19 0.47 -0.009 0.52
      bv059bd 54129 -0.04 0.39 -0.022 0.51
      bw086d 54127 -0.05 0.36 -0.010 0.39
      bw088a 54128 -0.02 0.37 -0.017 0.45
      ba068f 54154 -0.02 0.34 -0.009 0.37
      ba082c 54157 -0.07 0.39 -0.007 0.41
      bb227b 54142 -0.09 0.29 -0.013 0.36
      bb238a 54150 -0.05 0.39 -0.004 0.40
      bb238b 54152 -0.09 0.46 0.014 0.51
      bb238c 54153 -0.02 0.34 -0.004 0.35
      bc162 54155 0.02 0.34 -0.007 0.36
      bd119 54150 -0.06 0.38 -0.006 0.40
      bd123a 54135 -0.08 0.36 -0.010 0.40
      bg162 54136 -0.05 0.37 -0.009 0.40
      bg169b 54133 -0.07 0.35 0.004 0.36
      bi033c 54135 -0.08 0.36 -0.010 0.40
      bk133a 54141 -0.12 0.30 -0.006 0.34
      bl137n 54137 0.01 0.43 -0.014 0.48
      bl147d 54155 0.02 0.34 -0.007 0.36
      bl150a 54141 -0.12 0.30 -0.005 0.33
      bm239d 54142 -0.09 0.29 -0.013 0.36
      bm247f 54144 -0.02 0.49 -0.002 0.49
      bm250 54143 -0.07 0.33 -0.015 0.41
      bm253b 54145 -0.06 0.37 -0.007 0.39
      bm257a 54141 -0.12 0.30 -0.005 0.33
      bp131c 54148 0.01 0.34 -0.008 0.36
      bp134c 54159 -0.06 0.39 -0.002 0.40
      bs166b 54160 -0.08 0.43 -0.008 0.45
      bt088d 54151 -0.10 0.38 0.008 0.41
      bv059ad 54157 -0.07 0.39 -0.006 0.41
      bw088b 54149 -0.06 0.36 -0.009 0.39
      bb225d 54181 -0.03 0.37 -0.004 0.38
      bb230b 54191 -0.16 0.37 -0.011 0.44
      bb247a 54190 -0.16 0.40 -0.012 0.47
      bb248 54170 -0.02 0.38 -0.021 0.49
      bc170aa 54187 -0.18 0.39 -0.008 0.45
      bd123b 54166 -0.13 0.28 0.002 0.31
      bd123c 54174 -0.04 0.33 -0.012 0.38
      bd123d 54180 -0.07 0.40 -0.007 0.42
      bh147 54179 -0.07 0.41 -0.016 0.48
      bj061b 54161 -0.05 0.45 -0.002 0.45
      bj062a 54184 -0.10 0.42 -0.014 0.48
      bk134a 54161 -0.05 0.45 -0.002 0.45
      bl122d 54190 -0.16 0.40 -0.012 0.47
      bl137o 54162 -0.07 0.39 -0.010 0.42
      bl137p 54188 -0.12 0.39 -0.007 0.42
      bm234d 54165 -0.04 0.38 -0.007 0.40
      bm247g 54171 -0.06 0.37 -0.004 0.38
      bm257b 54175 -0.02 0.34 -0.008 0.36
      br100ae 54176 -0.03 0.39 -0.013 0.44
      br100bd 54185 -0.12 0.45 -0.005 0.47
      br100fd 54178 -0.07 0.36 -0.017 0.45
      br120b 54164 -0.03 0.36 -0.010 0.39
      br121e 54170 -0.02 0.39 -0.008 0.41
      br121f 54177 -0.04 0.38 -0.016 0.45
      br121g 54185 -0.12 0.45 -0.007 0.48
      br123a 54175 -0.02 0.34 -0.007 0.36
      br123b 54176 -0.03 0.39 -0.013 0.44
      br123c 54177 -0.04 0.38 -0.017 0.46
      br123d 54178 -0.07 0.36 -0.017 0.45
      bs171 54170 -0.02 0.38 -0.021 0.49
      bs174a 54163 -0.04 0.35 -0.013 0.40
      bs174b 54165 -0.04 0.38 -0.007 0.40
      bw088d 54173 -0.05 0.37 -0.011 0.41
      gt007 54174 -0.04 0.32 -0.012 0.37
      bb230c 54193 -0.17 0.42 0.006 0.46
      bb230d 54201 -0.12 0.31 -0.005 0.34
      bb231e 54198 -0.12 0.40 -0.011 0.45
      bb231f 54199 -0.17 0.45 -0.012 0.51
      bb231g 54200 -0.08 0.41 -0.008 0.43
      bb231h 54220 -0.15 0.39 -0.003 0.42
      bb241 54216 -0.15 0.39 -0.009 0.44
      bb243 54192 -0.13 0.40 -0.007 0.43
      bb247b 54192 -0.13 0.40 -0.004 0.42
      bd121 54212 -0.15 0.42 -0.010 0.47
      bd122 54211 -0.15 0.44 -0.012 0.50
      bk134c 54221 -0.14 0.42 -0.001 0.44
      bl137q 54209 -0.17 0.43 -0.003 0.46
      bl150b 54204 -0.18 0.42 -0.012 0.49
      bl150c 54210 -0.24 0.35 -0.018 0.50
      bl150d 54214 -0.10 0.39 0.001 0.40
      bl150e 54218 -0.17 0.41 -0.007 0.46
      bm244m 54204 -0.18 0.42 -0.012 0.49
      bm244n 54218 -0.17 0.41 -0.007 0.46
      bm244o 54219 -0.17 0.38 -0.003 0.42
      bm247h 54202 -0.18 0.40 -0.002 0.44
      br100dh 54210 -0.24 0.35 -0.019 0.51
      br100ed 54207 -0.15 0.41 -0.006 0.45
      br106d 54205 -0.16 0.42 -0.009 0.47
      br121h 54206 -0.15 0.40 -0.007 0.44
      br121i 54213 -0.15 0.39 -0.008 0.43
      br124a 54192 -0.13 0.41 -0.028 0.60
      br124b 54196 -0.17 0.40 -0.003 0.44
      br124c 54202 -0.17 0.41 -0.002 0.44
      bs172a 54200 -0.17 0.47 -0.011 0.53
      bt087d 54205 -0.16 0.42 -0.008 0.47
      bw086e 54217 -0.21 0.46 -0.017 0.57
      bw088e 54194 -0.14 0.45 -0.005 0.48
      bw088f 54213 -0.15 0.39 -0.004 0.42
      ba078c 54231 -0.13 0.46 -0.012 0.51
      bb232b 54246 -0.13 0.40 -0.007 0.43
      bb246a 54247 -0.14 0.40 -0.009 0.44
      bb246b 54252 -0.06 0.38 -0.011 0.42
      bc157d 54245 -0.11 0.45 -0.004 0.47
      bc167c 54249 -0.14 0.39 -0.007 0.43
      bc170ab 54246 -0.13 0.40 -0.007 0.43
      be050a 54236 -0.11 0.40 -0.006 0.42
      be050b 54237 -0.12 0.40 0.031 0.62
      be050c 54238 -0.21 0.30 -0.011 0.40
      be050d 54239 -0.13 0.42 -0.005 0.45
      be050e 54240 -0.12 0.42 -0.001 0.44
      be050f 54241 -0.14 0.40 -0.024 0.56
      be050g 54242 -0.19 0.38 0.016 0.49
      be050h 54243 -0.07 0.38 -0.006 0.40
      be050i 54244 -0.14 0.41 0.004 0.44
      be050j 54245 -0.11 0.45 -0.003 0.47
      bg175a 54247 -0.14 0.40 -0.009 0.44
      bg175b 54248 -0.15 0.39 -0.010 0.44
      bk133b 54244 -0.14 0.41 0.004 0.44
      bk134d 54224 -0.18 0.34 -0.009 0.41
      bm247i 54227 -0.13 0.39 -0.004 0.42
      bm247j 54252 -0.06 0.38 -0.011 0.42
      bp131d 54230 -0.09 0.39 -0.005 0.41
      bp134d 54242 -0.19 0.38 0.018 0.50
      bp137aa 54225 -0.17 0.39 -0.003 0.43
      br120c 54226 -0.16 0.40 -0.004 0.43
      bs164a 54226 -0.16 0.40 -0.009 0.45
      bs164b 54249 -0.14 0.39 -0.007 0.43
      bw088g 54230 -0.10 0.38 -0.006 0.40
      bb225e 54271 -0.07 0.38 0.011 0.42
      bb236a 54274 -0.07 0.37 0.000 0.38
      bc167d 54258 -0.15 0.47 -0.011 0.52
      bc169 54261 -0.05 0.37 0.002 0.37
      bd124a 54274 -0.07 0.37 0.000 0.38
      bd124b 54275 -0.05 0.35 0.001 0.35
      bd125a 54267 -0.09 0.36 0.002 0.37
      bj061c 54259 -0.17 0.19 0.001 0.26
      bj062b 54258 -0.15 0.47 -0.011 0.52
      bk134e 54253 -0.16 0.42 -0.004 0.45
      bk135 54267 -0.09 0.36 0.003 0.37
      bl149aa 54255 -0.10 0.40 -0.007 0.43
      bl149ab 54262 -0.05 0.37 0.006 0.38
      bl152a 54260 -0.06 0.45 0.001 0.45
      bl152b 54266 -0.06 0.42 0.004 0.43
      bl152c 54270 -0.01 0.38 0.017 0.46
      bm256a 54265 -0.07 0.38 -0.003 0.39
      bm262 54263 -0.04 0.40 0.016 0.47
      bp140a 54276 -0.02 0.35 0.003 0.35
      br120d 54269 -0.07 0.34 0.007 0.36
      bs172b 54276 -0.01 0.35 0.002 0.35
      bt087e 54275 -0.05 0.35 0.001 0.35
      bt093aa 54256 -0.10 0.46 -0.005 0.48
      bt093ba 54257 -0.14 0.47 -0.003 0.49
      bt093bb 54261 -0.11 0.42 -0.004 0.44
      bt093bc 54265 -0.07 0.38 -0.003 0.39
      bt093bd 54269 -0.07 0.34 0.007 0.36
      bt093be 54273 -0.03 0.22 0.008 0.25
      bt093bf 54277 0.00 0.37 -0.012 0.41
      bt093bg 54281 -0.07 0.32 0.002 0.33
      bt094a 54282 -0.07 0.34 0.000 0.35
      bw086f 54268 -0.07 0.37 0.003 0.38
      bw088h 54254 -0.13 0.38 -0.005 0.41
      bw088i 54273 -0.03 0.22 0.008 0.25
      bb236c 54305 -0.09 0.46 -0.012 0.50
      bc168a 54283 -0.06 0.35 0.000 0.36
      bc170ac 54297 -0.04 0.34 0.028 0.54
      bg176a 54300 -0.08 0.38 0.002 0.39
      bk140 54296 -0.07 0.37 0.008 0.40
      bl149ac 54285 -0.02 0.38 0.009 0.40
      bl149ad 54298 -0.09 0.43 0.009 0.46
      bm227c 54303 -0.08 0.41 0.006 0.43
      bm256b 54294 -0.07 0.40 -0.004 0.41
      bp131e 54283 -0.06 0.35 0.000 0.36
      bp140b 54304 -0.09 0.41 0.001 0.42
      br127a 54287 0.02 0.39 0.002 0.39
      br127b 54288 -0.02 0.38 -0.004 0.39
      br127c 54289 -0.02 0.35 0.004 0.36
      br127d 54290 -0.09 0.34 0.009 0.38
      br127e 54291 -0.07 0.31 0.031 0.56
      bt093bh 54285 -0.02 0.38 0.017 0.46
      bt093ca 54292 -0.07 0.29 -0.002 0.30
      bt093cb 54302 -0.08 0.43 0.004 0.44
      bt093cc 54313 0.13 -0.29 -0.003 0.32
      bw086g 54307 -0.10 0.38 -0.001 0.39
      bw088j 54297 -0.04 0.34 0.028 0.54
      bb246c 54325 0.18 -0.24 0.014 0.37
      bb246d 54330 0.19 -0.27 0.001 0.33
      bc167e 54333 0.20 -0.30 0.011 0.40
      bc167f 54336 0.11 -0.27 0.018 0.40
      bc170ba 54340 0.11 -0.31 0.022 0.47
      bc173 54338 0.16 -0.28 -0.002 0.32
      bg176b 54344 0.15 -0.25 -0.002 0.29
      bh146b 54326 0.15 -0.21 0.016 0.35
      bh147b 54323 0.16 -0.29 0.005 0.34
      bj062c 54316 0.16 -0.28 0.001 0.32
      bk133c 54316 0.16 -0.28 0.001 0.32
      bk141 54330 0.19 -0.28 0.008 0.36
      bl146b 54336 0.11 -0.27 0.018 0.40
      bl146c 54342 0.13 -0.25 -0.001 0.28
      bl149ae 54322 0.12 -0.22 -0.010 0.29
      bl149af 54329 0.13 -0.27 0.023 0.46
      bl149am 54337 0.18 -0.26 0.002 0.32
      bm256c 54319 0.22 -0.22 -0.010 0.35
      bm256d 54343 0.20 -0.27 -0.008 0.36
      bp134e 54318 0.14 -0.24 -0.006 0.29
      bp137ab 54317 0.16 -0.29 0.005 0.34
      br120e 54324 0.17 -0.26 0.012 0.36
      bs160c 54332 0.14 -0.23 0.001 0.27
      bt093cd 54321 0.13 -0.30 -0.018 0.42
      bt093ce 54331 0.16 -0.27 -0.002 0.32
      bt093cf 54342 0.13 -0.25 -0.001 0.28
      bw088k 54317 0.16 -0.29 0.005 0.34
      bw088l 54339 0.11 -0.30 0.000 0.32
      ba084a 54367 0.13 -0.27 -0.006 0.31
      bb246e 54347 0.14 -0.26 0.002 0.30
      bb246f 54347 0.14 -0.26 0.002 0.30
      bb246g 54359 0.16 -0.27 -0.003 0.32
      bb246h 54359 0.16 -0.27 -0.003 0.32
      bc170bb 54361 0.12 -0.27 -0.021 0.43
      bd126 54374 0.14 -0.28 -0.002 0.31
      bg173a 54371 0.19 -0.36 0.020 0.51
      bg173b 54370 0.17 -0.25 0.001 0.30
      bl146d 54349 0.14 -0.27 0.006 0.32
      bl146e 54355 0.22 -0.23 0.020 0.44
      bl146f 54360 0.15 -0.24 -0.006 0.30
      bl146g 54365 0.10 -0.26 -0.030 0.53
      bl146h 54371 0.19 -0.36 0.020 0.51
      bl149ag 54350 0.19 -0.22 -0.002 0.29
      bl157a 54353 0.16 -0.26 0.006 0.32
      bl157b 54359 0.16 -0.27 -0.003 0.32
      bl157c 54366 0.12 -0.25 -0.003 0.28
      bm256e 54373 0.16 -0.30 -0.004 0.35
      bp131f 54352 0.16 -0.26 -0.003 0.31
      bp141a 54348 0.19 -0.19 0.019 0.39
      bp141b 54350 0.19 -0.22 -0.002 0.29
      bp141c 54352 0.16 -0.26 -0.003 0.31
      bp141d 54354 0.09 -0.24 0.012 0.31
      bp141e 54356 0.16 -0.30 0.002 0.34
      br121k 54374 0.14 -0.28 -0.002 0.31
      br121m 54372 0.14 -0.25 0.005 0.30
      bs172c 54358 0.16 -0.29 0.006 0.34
      bt087f 54366 0.12 -0.25 -0.003 0.28
      bt093ab 54347 0.14 -0.26 0.002 0.30
      bt093cg 54353 0.16 -0.26 0.006 0.32
      bt093ch 54365 0.10 -0.26 0.002 0.28
      bv062 54368 0.15 -0.25 0.025 0.48
      bw086h 54356 0.16 -0.31 0.003 0.35
      bw088m 54364 0.07 -0.19 -0.020 0.36
      bb240a 54378 0.19 -0.22 -0.024 0.46
      bb240b 54382 0.17 -0.25 0.001 0.30
      bb240c 54402 0.15 -0.22 -0.001 0.27
      bb240d 54404 0.08 -0.31 -0.008 0.34
      bc168b 54396 0.19 -0.24 -0.002 0.31
      bd128a 54396 0.19 -0.24 -0.002 0.31
      bd130 54402 0.15 -0.22 -0.001 0.27
      bg176c 54385 0.18 -0.28 0.004 0.34
      bj062d 54379 0.19 -0.25 -0.007 0.33
      bl146i 54377 0.16 -0.23 -0.013 0.34
      bl146j 54383 0.20 -0.19 0.006 0.29
      bl146k 54391 0.16 -0.20 0.012 0.31
      bl146l 54397 0.18 -0.23 -0.011 0.34
      bl146m 54401 0.16 -0.22 -0.011 0.32
      bl155a 54394 0.16 -0.24 0.002 0.29
      bm264a 54395 0.18 -0.23 0.010 0.33
      br120f 54375 0.10 -0.16 0.011 0.25
      br121n 54390 0.12 -0.30 0.008 0.34
      br129aa 54392 0.21 -0.33 -0.027 0.56
      br129ba 54395 0.18 -0.23 0.010 0.33
      br129ca 54401 0.16 -0.22 -0.011 0.32
      bs179a 54380 0.18 -0.26 0.001 0.32
      bs179b 54404 0.08 -0.31 -0.007 0.34
      bt093da 54393 0.17 -0.23 -0.009 0.32
      bt093db 54403 0.18 -0.27 -0.015 0.39
      bw088n 54381 0.18 -0.26 -0.003 0.32
      bw088o 54400 0.16 -0.24 -0.128 1.94
      gl030 54393 0.15 -0.23 -0.002 0.28
      bb240e 54413 0.04 0.09 -0.004 0.12
      bb240f 54424 0.01 0.16 -0.008 0.20
      bb240g 54429 -0.06 0.14 -0.002 0.16
      bb242b 54418 -0.01 0.10 0.005 0.13
      bc170bc 54426 -0.07 0.20 -0.002 0.21
      bg176d 54434 -0.13 0.02 0.011 0.21
      bg182a 54408 0.19 -0.23 0.003 0.30
      bg182b 54412 0.17 -0.29 0.018 0.43
      bg182c 54435 -0.06 0.14 -0.001 0.15
      bl146n 54422 -0.03 0.12 0.000 0.12
      bm256f 54406 0.11 -0.26 0.000 0.28
      bm264b 54411 0.17 -0.23 0.000 0.29
      bm264c 54429 -0.07 0.14 -0.008 0.20
      bm264d 54411 0.17 -0.23 0.000 0.29
      bm264e 54430 -0.03 0.12 0.011 0.21
      br129da 54409 0.13 -0.26 -0.003 0.29
      bs175a 54414 -0.05 0.10 -0.002 0.12
      bs175b 54415 0.00 0.09 0.005 0.12
      bs175c 54416 -0.02 0.21 -0.001 0.21
      bs175d 54417 -0.12 0.26 -0.003 0.29
      bt093dc 54412 -0.03 0.13 0.008 0.18
      bt093dd 54423 -0.04 0.15 -0.001 0.16
      bt093de 54434 -0.13 0.02 0.011 0.21
      bw088p 54407 0.18 -0.24 0.000 0.30
      bw088q 54422 -0.03 0.12 0.000 0.12
      gb062 54409 0.13 -0.26 -0.003 0.29
      bb240h 54436 -0.07 0.13 -0.008 0.19
      bb240i 54443 -0.05 0.11 -0.008 0.17
      bb240k 54456 -0.05 0.13 -0.013 0.24
      bb240l 54464 -0.02 0.18 -0.017 0.31
      bb242a 54442 -0.07 0.15 -0.001 0.17
      bc167g 54449 -0.05 0.15 -0.001 0.16
      bc167h 54455 -0.07 0.17 -0.011 0.25
      bd129a 54448 -0.13 0.05 0.004 0.15
      bd130b 54451 -0.03 0.12 -0.005 0.14
      bg168 54437 -0.06 0.10 -0.005 0.14
      bg170a 54438 -0.07 0.22 -0.013 0.30
      bj062e 54442 -0.07 0.15 -0.002 0.17
      bj064 54443 -0.05 0.11 -0.008 0.17
      bl156 54457 -0.04 0.14 -0.006 0.17
      bm264f 54456 -0.03 0.14 -0.013 0.24
      bm264g 54458 0.00 0.16 -0.002 0.16
      bs172d 54452 -0.10 0.21 0.020 0.38
      bt093ac 54439 -0.05 0.12 -0.011 0.21
      bt093df 54442 -0.07 0.15 -0.002 0.17
      bt093dg 54452 -0.10 0.21 0.020 0.38
      bt093dh 54462 -0.08 0.22 0.001 0.23
      bt094b 54466 -0.05 0.17 -0.012 0.25
      bw088r 54445 -0.13 0.23 -0.008 0.29
      bw088s 54450 -0.05 0.14 -0.005 0.17
      bw088t 54465 -0.03 0.19 -0.008 0.23
      ----------------------------------------------------
      Maximum difference between used and final EOPs:
      XPOLE: 0.24 mas; YPOLE: 0.49 mas; UT1-UTC: 0.128000000004 milliseconds; combined: 1.94 mas.

      From 346 projects, 185 (100) have differences larger than 0.10 (0.15) mas in XPOLE.
      From 346 projects, 339 (320) have differences larger than 0.10 (0.15) mas in YPOLE.
      From 346 projects, 109 (7) have differences larger than 10 (30) microseconds in UT1-UTC.

      

      EOP difference 2008

      by Amy Mioduszewski last modified Aug 18, 2011
      Difference in EOPs from correlation and the best USNO numbers from all the experiments in 2008.
        Obs     MJD    diff X   diff Y  diff UT1  combined
      [mas] [mas] [ms] [mas]
      ----------------------------------------------------
      ba078d 54478 -0.06 0.16 -0.006 0.19
      bb240m 54473 -0.03 0.21 0.005 0.22
      bb240n 54482 -0.06 0.16 -0.001 0.17
      bb240o 54491 -0.06 0.17 -0.002 0.18
      bb242c 54481 -0.06 0.14 -0.002 0.16
      bb242d 54487 -0.03 0.16 -0.020 0.34
      bc170bd 54484 -0.04 0.21 -0.010 0.26
      bd128b 54480 0.04 0.27 0.016 0.36
      bg176e 54477 -0.08 0.16 -0.026 0.43
      bj061d 54478 -0.06 0.16 -0.006 0.19
      bl155b 54472 -0.05 0.16 -0.007 0.20
      bm256g 54483 0.03 0.26 -0.009 0.29
      bm269a 54494 -0.08 0.12 -0.010 0.21
      bm273a 54473 -0.03 0.21 0.001 0.21
      bm273b 54477 -0.08 0.16 -0.030 0.48
      bm273c 54478 -0.06 0.16 -0.018 0.32
      bm273d 54479 -0.01 0.15 0.005 0.17
      br120g 54477 -0.08 0.16 -0.030 0.48
      br131a 54493 -0.02 0.16 -0.006 0.18
      br131b 54495 -0.03 0.14 -0.004 0.16
      bt093di 54482 -0.06 0.16 -0.000 0.17
      bt094c 54485 -0.03 0.16 -0.022 0.37
      bw086i 54469 -0.00 0.31 -0.008 0.33
      bw088u 54487 -0.03 0.16 -0.020 0.34
      bw090a 54492 -0.03 0.15 -0.001 0.15
      bw090b 54497 0.03 0.11 0.009 0.18
      bb240p 54498 -0.01 0.18 0.003 0.19
      bb240q 54504 -0.20 0.09 0.001 0.22
      bb240r 54511 -0.08 0.25 -0.009 0.30
      bb240s 54517 -0.13 0.13 -0.003 0.19
      bb240t 54525 -0.05 0.16 -0.009 0.22
      bc168c 54521 -0.02 0.13 -0.001 0.13
      bd132a 54511 -0.08 0.25 -0.009 0.30
      bd132b 54516 -0.07 0.13 -0.019 0.32
      bg170b 54500 -0.07 0.14 -0.014 0.26
      bg176f 54518 0.02 0.17 -0.015 0.28
      bh146c 54515 -0.02 0.18 -0.007 0.21
      bh151a 54499 -0.05 0.11 -0.004 0.13
      bh151b 54506 -0.06 0.15 -0.003 0.17
      bh151c 54510 -0.03 0.13 -0.003 0.14
      bk142a 54514 -0.04 0.17 -0.004 0.18
      bk146a 54524 -0.05 0.10 -0.008 0.16
      bl158a 54519 -0.08 0.14 -0.014 0.26
      bl158c 54505 -0.07 0.11 -0.002 0.13
      bl158d 54513 -0.05 0.15 -0.004 0.17
      bl159 54523 -0.04 0.08 -0.001 0.09
      bm256h 54525 -0.05 0.16 -0.007 0.20
      br125b 54507 -0.10 0.15 -0.008 0.22
      bs160d 54514 -0.04 0.17 -0.004 0.18
      bs179c 54520 -0.06 0.17 -0.001 0.18
      bs181 54505 -0.07 0.12 -0.002 0.14
      bw090c 54501 0.02 0.21 -0.024 0.42
      bw090d 54507 -0.10 0.15 -0.008 0.22
      bw090e 54512 -0.05 0.14 -0.005 0.17
      bw090f 54517 -0.13 0.13 -0.003 0.19
      bw090g 54522 -0.09 0.17 0.001 0.19
      bb240u 54529 -0.07 0.25 0.012 0.32
      bb240v 54543 -0.11 0.23 0.036 0.60
      bb240w 54547 1.62 1.11 -0.013 1.97
      bb240x 54552 3.01 2.89 -0.512 8.74
      bb251 54556 1.52 1.74 -1.005 15.25
      bb254a 54550 3.00 2.65 -0.293 5.94
      bb254b 54550 3.00 2.65 -0.293 5.94
      bb254c 54550 3.00 2.65 -0.293 5.94
      bc170be 54549 2.83 2.31 -0.180 4.54
      bc178 54547 1.62 1.11 -0.013 1.97
      bc184a 54529 -0.08 0.16 -0.004 0.19
      bd129b 54531 -0.03 0.14 -0.002 0.15
      bd131a 54537 -0.07 0.23 0.011 0.29
      bd131b 54539 -0.11 0.21 -0.007 0.26
      bf092aa 54552 3.01 2.89 -0.512 8.74
      bk143a 54539 -0.11 0.21 -0.007 0.26
      bk146b 54543 -0.11 0.23 0.036 0.60
      bk146c 54542 -0.02 0.17 0.002 0.17
      bl158b 54542 -0.02 0.17 0.002 0.17
      bm270 54549 2.83 2.31 -0.180 4.54
      bo030a 54548 2.33 1.79 -0.087 3.21
      bs176a 54545 0.47 0.20 0.046 0.86
      bt097a 54540 -0.04 0.15 0.002 0.16
      bw090h 54528 -0.04 0.12 -0.004 0.14
      bw090i 54532 -0.05 0.29 0.006 0.31
      bw090j 54538 -0.05 0.14 0.000 0.15
      bw090k 54545 0.47 0.20 0.046 0.86
      bw090l 54550 3.00 2.65 -0.293 5.94
      bw090m 54555 1.67 2.33 -0.846 13.01
      gc025b 54535 -0.08 0.12 -0.006 0.17
      gc030 54534 -0.05 0.13 -0.004 0.15
      bb240aa 54572 -0.07 0.16 -0.001 0.18
      bb240ab 54580 -0.12 0.14 0.003 0.19
      bb240ac 54585 -0.15 0.25 0.009 0.32
      bb240ad 54586 -0.10 0.11 0.014 0.26
      bb240y 54564 3.38 0.42 -2.669 40.18
      bb240z 54567 1.70 1.51 -2.936 44.10
      bb242e 54571 -0.07 0.24 -0.002 0.25
      bb242f 54570 -0.07 0.17 -0.003 0.19
      bb242g 54573 -0.09 0.15 0.001 0.18
      bb242h 54576 -0.09 0.19 -0.006 0.23
      bb242i 54578 -0.11 0.16 -0.001 0.19
      bc184b 54564 3.38 0.42 -2.669 40.18
      bd125b 54573 -0.09 0.15 0.001 0.18
      bd128c 54576 -0.07 0.14 -0.004 0.17
      bf092ba 54566 2.17 1.32 -2.915 43.80
      bi037a 54578 -0.11 0.16 -0.001 0.19
      bk151 54564 3.38 0.42 -2.669 40.18
      bl155c 54562 2.69 0.37 -2.201 33.13
      bl156b 54577 -0.11 0.15 -0.005 0.20
      bm257c 54587 -0.08 0.16 0.001 0.18
      bm267a 54563 3.11 0.25 -2.474 37.24
      bm282 54558 1.41 1.09 -1.390 20.93
      bm283 54583 -0.08 0.16 0.003 0.18
      bo030b 54584 -0.05 0.14 0.003 0.16
      bp137ac 54569 1.02 1.33 -2.766 41.52
      br120h 54561 2.47 0.58 -1.920 28.91
      br129ab 54574 -0.06 0.26 0.006 0.28
      br129bb 54575 -0.08 0.21 -0.004 0.23
      br129cb 54581 0.01 0.16 0.003 0.17
      br129db 54582 -0.09 0.15 -0.001 0.18
      bs172e 54574 -0.08 0.17 -0.004 0.20
      bw090n 54562 2.69 0.37 -2.201 33.13
      bb240ae 54603 -0.08 0.12 -0.005 0.16
      bb240af 54611 -0.07 0.21 -0.004 0.23
      bb240ag 54617 -0.07 0.19 -0.010 0.25
      bb242j 54610 -0.11 0.19 -0.009 0.26
      bb255a 54590 -0.10 0.15 -0.002 0.18
      bb255ba 54590 -0.10 0.15 -0.002 0.18
      bb255bb 54590 -0.10 0.15 -0.002 0.18
      bb255bc 54591 -0.12 0.16 -0.002 0.20
      bb255bd 54591 -0.12 0.16 -0.002 0.20
      bb255be 54591 -0.12 0.16 -0.002 0.20
      bb259 54608 -0.15 0.19 0.012 0.30
      bc170bf 54614 -0.09 0.19 -0.016 0.32
      bc174a 54590 -0.08 0.15 -0.002 0.17
      bc174b 54591 -0.12 0.16 -0.002 0.20
      bc174c 54595 -0.05 0.14 0.002 0.15
      bc174d 54601 -0.07 0.14 -0.013 0.25
      bc184c 54613 -0.05 0.16 -0.015 0.28
      bd120a 54604 -0.06 0.19 -0.001 0.20
      bd120b 54604 -0.06 0.19 -0.001 0.20
      bd120c 54604 -0.06 0.19 -0.001 0.20
      bd120d 54605 -0.05 0.17 -0.003 0.18
      bd120e 54605 -0.05 0.17 -0.003 0.18
      bd120f 54605 -0.05 0.17 -0.003 0.18
      bd135a 54592 -0.01 0.17 -0.014 0.27
      bd135b 54597 -0.07 0.14 -0.001 0.16
      bd135c 54600 -0.07 0.14 -0.003 0.16
      bd135d 54604 -0.06 0.19 -0.001 0.20
      bd135e 54606 -0.14 0.19 0.011 0.29
      bd135f 54607 -0.02 0.16 0.017 0.30
      bd135g 54609 0.11 0.28 0.008 0.32
      bd135h 54610 -0.08 0.12 -0.009 0.20
      bd135i 54612 0.95 0.81 0.554 8.40
      bd135j 54612 -0.05 0.17 -0.006 0.20
      bh151d 54614 -0.07 0.17 -0.007 0.21
      bi037b 54616 -0.11 0.14 -0.017 0.31
      bj062f 54609 0.08 0.24 -0.002 0.25
      bl149ai 54617 -0.07 0.19 -0.011 0.26
      bl149ao 54588 -0.09 0.15 -0.002 0.18
      bl161 54616 -0.11 0.14 -0.019 0.34
      bm257d 54588 -0.09 0.15 -0.002 0.18
      bm269b 54611 -0.07 0.21 -0.004 0.23
      br120i 54614 -0.09 0.19 -0.016 0.32
      br130a 54591 -0.12 0.16 -0.002 0.20
      bt094e 54602 0.05 0.25 -0.018 0.37
      bw089 54592 -0.01 0.17 -0.014 0.27
      by122a 54592 -0.01 0.17 -0.014 0.27
      by122b 54593 -0.06 0.14 -0.002 0.16
      by122c 54597 -0.07 0.14 -0.001 0.16
      by122d 54598 -0.04 0.16 0.001 0.17
      bz036a 54612 -0.05 0.17 -0.005 0.19
      gm064 54619 -0.05 0.10 -0.007 0.15
      ba084b 54632 -0.10 0.14 -0.002 0.17
      bb240ah 54638 -0.05 0.12 -0.002 0.13
      bb240ai 54646 -0.06 0.15 -0.000 0.16
      bb250 54640 -0.12 0.13 -0.003 0.18
      bb258a 54626 -0.08 0.13 -0.001 0.15
      bc184d 54641 0.04 0.14 -0.006 0.17
      bd128d 54641 0.10 0.20 -0.011 0.28
      bd134a 54620 -0.06 0.21 0.005 0.23
      bf092ca 54626 -0.08 0.13 -0.001 0.15
      bj061e 54631 -0.07 0.12 -0.003 0.15
      bl149aj 54643 -0.06 0.10 -0.007 0.16
      bl155d 54648 0.03 0.20 -0.007 0.23
      bl160a 54647 -0.13 0.12 -0.005 0.19
      bm256i 54630 -0.07 0.11 -0.000 0.13
      bm267b 54637 -0.10 0.17 -0.005 0.21
      bp147 54640 -0.08 0.08 -0.001 0.11
      br125c 54637 -0.19 0.15 -0.015 0.33
      br125d 54638 -0.06 0.12 -0.003 0.14
      br130b 54634 -0.09 0.23 -0.005 0.26
      bs176b 54622 -0.04 0.15 -0.001 0.16
      bt094f 54644 -0.03 0.19 -0.026 0.43
      bt097b 54621 -0.07 0.18 0.005 0.21
      by124a 54633 -0.10 0.09 -0.002 0.14
      by124b 54634 -0.09 0.23 -0.005 0.26
      ba078e 54653 -0.05 0.14 -0.001 0.15
      bb240aj 54651 -0.08 0.13 -0.013 0.25
      bb240ak 54656 -0.14 0.12 -0.002 0.19
      bb240am 54667 -0.07 0.18 -0.002 0.20
      bb240an 54671 -0.03 0.17 -0.005 0.19
      bb240xl 54663 -0.06 0.13 -0.009 0.20
      bb253 54667 -0.07 0.18 -0.002 0.20
      bb265 54671 -0.03 0.17 -0.013 0.26
      bd134b 54677 -0.11 0.11 -0.008 0.20
      bi035a 54669 0.00 0.21 -0.018 0.34
      bl149ak 54665 -0.06 0.11 -0.032 0.50
      bl149al 54678 -0.10 0.14 -0.005 0.19
      bl151a 54658 -0.09 0.12 -0.051 0.78
      bl155e 54665 -0.06 0.11 -0.032 0.50
      bm256j 54654 -0.10 0.15 0.000 0.18
      bm267c 54652 -0.07 0.14 -0.004 0.17
      bm267d 54660 -0.09 0.15 -0.006 0.20
      bm267e 54675 -0.13 0.13 -0.007 0.21
      bm291 54654 -0.10 0.15 0.000 0.18
      br130c 54674 -0.08 0.17 -0.010 0.24
      by122e 54673 -0.05 0.16 -0.022 0.37
      by122f 54674 -0.08 0.17 -0.010 0.24
      bb240ao 54680 -0.08 0.15 -0.007 0.20
      bb240ap 54687 -0.11 0.18 -0.014 0.30
      bb240aq 54691 -0.07 0.16 -0.023 0.39
      bb240ar 54695 -0.12 0.25 -0.008 0.30
      bb240as 54697 -0.10 0.24 -0.009 0.29
      bb240at 54702 -0.04 0.22 -0.002 0.23
      bb240au 54710 -0.08 0.15 0.000 0.17
      bb258b 54697 -0.10 0.24 -0.007 0.28
      bb258c 54701 -0.06 0.19 0.000 0.20
      bc174e 54686 0.04 0.16 -0.021 0.36
      bc174f 54689 -0.09 0.14 -0.009 0.21
      bc184e 54682 -0.07 0.11 -0.007 0.17
      bc184f 54707 -0.14 0.33 0.024 0.51
      bh146d 54683 -0.00 0.14 -0.007 0.17
      bh151e 54691 -0.07 0.16 -0.023 0.39
      bh157 54682 -0.07 0.11 -0.007 0.17
      bi035b 54708 -0.04 0.15 0.003 0.16
      bj061f 54680 -0.04 0.10 -0.007 0.15
      bk148a 54706 -0.05 0.16 -0.001 0.17
      bk148b 54709 -0.07 0.15 -0.007 0.20
      bl149ba 54685 -0.08 0.16 -0.011 0.24
      bl149bb 54704 -0.12 0.21 0.001 0.24
      bm256k 54694 -0.12 0.18 -0.002 0.22
      bm267f 54696 -0.13 0.23 -0.012 0.32
      bm269c 54681 -0.08 0.13 0.001 0.15
      bo031 54682 -0.07 0.11 -0.007 0.17
      bs160e 54683 -0.00 0.14 -0.007 0.17
      bs176c 54707 -0.14 0.33 0.023 0.50
      bt097c 54698 -0.09 0.18 -0.047 0.73
      bz036b 54692 -0.07 0.17 -0.014 0.28
      ba088 54736 -0.11 0.12 -0.007 0.19
      bb240av 54713 -0.18 0.21 0.026 0.48
      bb240aw 54718 -0.07 0.23 0.015 0.33
      bb240ax 54721 -0.11 0.10 0.006 0.17
      bb240ay 54727 -0.03 0.15 -0.011 0.23
      bb258d 54732 -0.03 0.19 0.000 0.19
      bc184g 54735 -0.06 0.06 -0.013 0.21
      bd128e 54711 -0.07 0.13 -0.001 0.15
      bd134c 54737 -0.08 0.13 -0.004 0.16
      bf092ab 54725 0.20 0.25 0.000 0.32
      bf092bb 54728 -0.19 0.07 -0.000 0.20
      bi036a 54715 -0.08 0.13 -0.003 0.16
      bi037c 54739 -0.10 0.14 0.008 0.21
      bk148c 54717 -0.04 0.18 -0.005 0.20
      bk148d 54716 -0.07 0.20 -0.003 0.22
      bk150a 54711 -0.07 0.13 -0.001 0.15
      bk150b 54715 -0.08 0.13 -0.003 0.16
      bl149bc 54722 -0.11 0.15 -0.003 0.19
      bl160b 54724 -0.15 0.14 -0.002 0.21
      bm256l 54720 -0.08 0.16 0.008 0.22
      bm284a 54739 -0.10 0.14 0.008 0.21
      bm286e 54736 -0.11 0.12 -0.007 0.19
      bp137ad 54725 0.20 0.25 0.002 0.32
      bp146a 54729 -0.04 0.16 -0.004 0.18
      br129ac 54723 -0.10 0.13 -0.006 0.19
      br129bc 54731 -0.13 0.14 -0.003 0.20
      br130d 54716 -0.07 0.20 -0.003 0.22
      bb240az 54743 -0.14 0.15 -0.003 0.21
      bb240ba 54744 -0.11 0.18 -0.003 0.22
      bb240bb 54767 0.01 0.26 -0.008 0.29
      bb257a 54747 -0.10 0.16 0.008 0.22
      bb263 54747 -0.10 0.16 0.008 0.22
      bd128f 54758 -0.09 0.15 -0.001 0.18
      bf092ac 54741 -0.09 0.15 -0.007 0.20
      bf092bc 54755 -0.10 0.12 0.005 0.17
      bg189a 54768 -0.09 0.16 -0.003 0.19
      bh161 54761 -0.11 0.13 -0.002 0.17
      bk150c 54741 -0.09 0.15 -0.007 0.20
      bk150d 54763 -0.01 0.17 -0.022 0.37
      bk153b 54747 -0.10 0.16 0.008 0.22
      bk153c 54748 -0.07 0.14 0.010 0.22
      bl149bd 54743 -0.14 0.14 -0.003 0.20
      bl155f 54748 -0.07 0.14 0.010 0.22
      bm272jb 54763 -0.01 0.17 -0.022 0.37
      bp150aa 54766 -0.11 0.15 -0.005 0.20
      br129cc 54771 -0.07 0.09 -0.003 0.12
      br129dc 54746 -0.11 0.22 0.018 0.37
      br130e 54767 0.01 0.26 -0.007 0.28
      br134aa 54759 -0.12 0.16 -0.003 0.21
      br134ba 54762 -0.12 0.15 0.001 0.19
      bw077c 54749 -0.07 0.27 -0.004 0.29
      gb067 54766 -0.11 0.15 -0.004 0.20
      ba089 54772 -0.08 0.14 0.001 0.16
      bb240bc 54774 0.01 0.18 -0.010 0.23
      bb240bd 54776 -0.14 0.14 -0.003 0.20
      bb240be 54780 -0.09 0.18 -0.007 0.23
      bb240bf 54787 -0.09 0.15 -0.008 0.21
      bb240bg 54791 0.00 0.15 -0.007 0.18
      bb240bh 54792 -0.08 0.17 -0.006 0.21
      bb240bi 54793 -0.07 0.15 -0.007 0.20
      bb242k 54792 -0.08 0.17 -0.006 0.21
      bb257 54789 -0.04 0.13 -0.000 0.14
      bb264b 54793 -0.07 0.15 -0.007 0.20
      bb264c 54794 -0.03 0.15 -0.006 0.18
      bc184h 54775 -0.16 0.14 -0.008 0.24
      bc184i 54801 -0.05 0.17 -0.013 0.26
      bc186a 54800 -0.08 0.18 -0.011 0.26
      bg189b 54778 -0.15 0.17 -0.005 0.24
      bi036b 54789 -0.04 0.13 0.001 0.14
      bi037d 54799 -0.09 0.13 -0.009 0.21
      bj061g 54782 -0.09 0.19 -0.004 0.22
      bk154 54784 0.04 0.17 -0.001 0.18
      bl149be 54790 -0.09 0.18 -0.004 0.21
      bl149bf 54797 -0.07 0.14 -0.004 0.17
      bl160c 54800 -0.08 0.18 -0.011 0.26
      bm269d 54776 -0.14 0.14 -0.003 0.20
      bm272ha 54781 -0.01 0.12 0.008 0.17
      bm272ia 54782 -0.09 0.19 0.000 0.21
      bm286a 54794 -0.03 0.15 -0.004 0.16
      bm290a 54788 -0.12 0.22 0.000 0.25
      bt097d 54785 -0.16 0.19 -0.004 0.26
      bz036c 54779 -0.08 0.17 -0.005 0.20
      bb240bj 54802 -0.08 0.16 -0.008 0.22
      bb240bk 54804 -0.07 0.16 -0.004 0.18
      bb240bl 54807 -0.05 0.15 -0.010 0.22
      bb240bm 54812 -0.05 0.11 -0.006 0.15
      bb240bn 54814 -0.05 0.11 -0.003 0.13
      bb240bo 54821 -0.07 0.13 -0.011 0.22
      bb240bp 54830 -0.12 0.17 0.009 0.25
      bb242l 54813 -0.09 0.16 -0.010 0.24
      bb262a 54831 0.02 0.08 0.000 0.08
      bb264e 54824 -0.05 0.10 -0.004 0.13
      bb264f 54825 -0.05 0.09 -0.012 0.21
      bc184j 54832 -0.07 0.12 -0.008 0.18
      bd141a 54817 -0.10 0.12 -0.004 0.17
      bf092cb 54801 -0.05 0.17 -0.013 0.26
      bf092cc 54816 -0.17 0.18 0.004 0.25
      bg192 54806 -0.05 0.09 -0.004 0.12
      bj068a 54821 -0.08 0.15 -0.013 0.26
      bj068b 54823 -0.05 0.08 -0.010 0.18
      bl151b 54819 -0.10 0.12 0.026 0.42
      bo033 54808 -0.08 0.16 -0.006 0.20
      bp143a 54805 -0.02 0.10 -0.004 0.12
      br130f 54806 -0.07 0.17 -0.004 0.19
      bs176d 54811 -0.05 0.20 0.010 0.25
      ----------------------------------------------------
      Maximum difference between used and final EOPs:
      XPOLE: 3.38 mas; YPOLE: 2.89 mas; UT1-UTC: 2.936 milliseconds; combined: 44.1 mas.

      From 351 projects, 102 (39) have differences larger than 0.10 (0.15) mas in XPOLE.
      From 351 projects, 337 (211) have differences larger than 0.10 (0.15) mas in YPOLE.
      From 351 projects, 94 (33) have differences larger than 10 (30) microseconds in UT1-UTC.

      

      EOP difference 2009

      by Amy Mioduszewski last modified Aug 18, 2011
      Difference in EOPs from correlation and the best USNO numbers from all the experiments in 2009.
        Obs     MJD    diff X   diff Y  diff UT1  combined
      [mas] [mas] [ms] [mas]
      ----------------------------------------------------
      ba078f 54849 -0.07 0.15 -0.011 0.23
      bb240bq 54835 -0.02 0.14 -0.004 0.15
      bb240br 54841 -0.08 0.11 -0.004 0.15
      bb240bs 54851 -0.10 0.15 -0.005 0.20
      bb240bt 54863 -0.07 0.12 -0.008 0.18
      bb242m 54843 -0.14 0.09 -0.008 0.21
      bb262b 54836 -0.07 0.17 -0.019 0.34
      bb262c 54841 -0.08 0.11 -0.004 0.15
      bb262d 54842 -0.10 0.10 -0.010 0.21
      bh152a 54846 -0.10 0.13 -0.016 0.29
      bk153d 54860 -0.08 0.09 0.000 0.12
      bl149bg 54839 -0.06 0.16 -0.002 0.17
      bl149bh 54862 -0.07 0.09 0.002 0.12
      bl155g 54836 -0.07 0.17 -0.019 0.34
      bm269e 54858 0.00 0.21 0.018 0.34
      bm286b 54850 -0.06 0.16 -0.013 0.26
      bp143b 54842 -0.08 0.10 -0.010 0.20
      bp146b 54834 -0.06 0.12 -0.003 0.14
      bp150b 54857 -0.12 0.09 -0.001 0.15
      br130g 54850 -0.06 0.16 -0.013 0.26
      br141a 54855 -0.09 0.14 -0.002 0.17
      bw092a 54851 -0.10 0.15 -0.005 0.20
      bz036d 54859 -0.06 0.08 0.005 0.13
      ba084c 54879 -0.08 0.09 -0.019 0.31
      bb240bu 54887 -0.37 0.25 0.012 0.48
      bb242q 54878 -0.09 0.14 -0.013 0.26
      bb261b 54881 -0.09 0.04 -0.005 0.12
      bb262e 54883 -0.09 0.14 -0.009 0.21
      bb262f 54890 -0.05 0.08 -0.010 0.18
      bb267a 54891 -0.06 0.13 -0.016 0.28
      bc184k 54864 -0.06 0.10 0.000 0.12
      bc185a 54870 -0.08 0.13 -0.010 0.21
      bc185b 54869 -0.09 0.11 -0.004 0.15
      bc185c 54871 -0.08 0.11 -0.006 0.16
      bc186b 54884 -0.11 0.13 -0.013 0.26
      bc188a 54864 -0.06 0.10 0.000 0.12
      bd141b 54877 -0.06 0.12 -0.011 0.21
      bf098a 54872 -0.03 0.08 -0.005 0.11
      bf098b 54873 -0.04 0.10 -0.002 0.11
      bf098c 54874 -0.05 0.10 -0.006 0.14
      bi036c 54869 -0.09 0.11 -0.004 0.15
      bi037e 54876 -0.06 0.11 -0.018 0.30
      bk150f 54865 0.04 0.17 0.026 0.43
      bk150g 54868 -0.15 0.12 0.007 0.22
      bl149bi 54888 -0.02 0.08 0.004 0.10
      bl160d 54890 -0.05 0.08 -0.010 0.18
      bm284b 54885 -0.05 0.12 -0.004 0.14
      bm290b 54878 -0.09 0.14 -0.023 0.38
      bp143c 54875 0.04 0.13 -0.035 0.54
      bs193a 54882 -0.01 0.12 -0.011 0.20
      bt097e 54877 -0.06 0.12 -0.011 0.21
      bt102 54876 -0.06 0.11 -0.018 0.30
      bv067c 54883 -0.09 0.14 -0.009 0.21
      bb240bv 54903 -0.04 0.14 -0.005 0.16
      bb261c 54911 -0.13 0.12 -0.005 0.19
      bb261d 54914 0.10 0.19 -0.006 0.23
      bb261e 54920 -0.08 0.10 -0.035 0.54
      bb267b 54892 -0.06 0.13 -0.015 0.27
      bc184l 54893 -0.18 0.14 0.014 0.31
      bf092ad 54910 -0.08 0.18 0.002 0.20
      bf092bd 54918 -0.05 0.13 -0.002 0.14
      bj068c 54907 -0.03 0.19 -0.003 0.20
      bl149bj 54916 -0.05 0.08 0.003 0.10
      bm257e 54912 -0.10 0.15 -0.008 0.22
      bm257f 54916 -0.05 0.08 0.003 0.10
      bm286c 54909 -0.11 0.14 0.003 0.18
      bm291b 54904 -0.06 0.08 -0.006 0.13
      bp150ac 54911 -0.13 0.12 -0.005 0.19
      br129ad 54914 0.10 0.19 -0.005 0.23
      br129bd 54919 -0.02 0.15 -0.023 0.38
      br130h 54899 -0.11 0.14 -0.012 0.25
      bs176e 54897 -0.08 0.18 -0.007 0.22
      bs192a 54920 -0.08 0.10 -0.035 0.54
      bs193b 54907 -0.07 0.25 0.017 0.36
      bv067a 54891 -0.06 0.13 -0.017 0.29
      bv067b 54906 -0.07 0.05 -0.010 0.17
      bv067d 54906 -0.07 0.05 -0.010 0.17
      bv067e 54896 -0.05 0.12 -0.001 0.13
      bw091a 54897 -0.07 0.18 -0.004 0.20
      bw092b 54904 -0.06 0.08 -0.006 0.13
      bb240bw 54929 -0.08 0.09 0.006 0.15
      bb240bx 54945 -0.10 0.12 -0.011 0.23
      bb242r 54939 -0.04 0.09 -0.012 0.21
      bb242s 54941 0.00 0.09 -0.009 0.16
      bb242t 54947 -0.06 0.10 -0.014 0.24
      bb255ca 54930 -0.04 0.16 -0.002 0.17
      bb255cb 54930 -0.04 0.16 -0.002 0.17
      bb255cc 54931 -0.06 0.15 -0.001 0.16
      bb255cd 54931 -0.06 0.14 -0.001 0.15
      bb255ce 54931 -0.06 0.15 -0.001 0.16
      bb255d 54932 -0.08 0.18 -0.007 0.22
      bb261f 54928 -0.04 0.24 0.001 0.24
      bb261g 54933 -0.05 0.09 -0.009 0.17
      bb261h 54940 -0.08 0.11 -0.015 0.26
      bb272 54952 -0.01 0.12 -0.010 0.19
      bc178b 54949 0.01 0.24 0.009 0.28
      bj061h 54946 -0.09 0.08 -0.011 0.20
      bk150h 54931 -0.07 0.15 0.000 0.17
      bk150i 54944 -0.04 0.15 0.000 0.16
      bk153e 54948 -0.05 0.09 -0.013 0.22
      bl155h 54929 -0.08 0.09 0.005 0.14
      bm272jc 54937 0.01 0.20 0.017 0.32
      bm272jd 54941 -0.02 0.13 -0.009 0.19
      bm290c 54948 -0.05 0.09 -0.013 0.22
      bp146c 54926 -0.06 0.15 -0.021 0.35
      br129cd 54938 -0.04 0.22 -0.003 0.23
      br129dd 54946 -0.09 0.08 -0.011 0.20
      br130i 54938 -0.04 0.22 -0.003 0.23
      br134ab 54930 -0.08 0.19 0.002 0.21
      br134ac 54937 0.01 0.20 0.017 0.32
      br134bb 54949 0.01 0.24 0.009 0.28
      br134bc 54952 -0.01 0.12 -0.010 0.19
      br141b 54935 -0.08 0.18 0.001 0.20
      bs192b 54936 -0.20 0.23 0.005 0.31
      bs193c 54943 -0.19 0.23 -0.006 0.31
      by126a 54923 -0.01 0.13 0.006 0.16
      by126b 54925 -0.06 0.20 -0.002 0.21
      by126c 54927 0.01 0.12 -0.010 0.19
      bb233b 54969 -0.02 0.12 -0.007 0.16
      bb240by 54970 -0.12 0.14 0.012 0.26
      bb240bz 54978 -0.11 0.23 0.022 0.42
      bb269a 54967 -0.05 0.15 -0.004 0.17
      bc186c 54973 -0.08 0.18 0.003 0.20
      bc188b 54953 -0.11 0.12 -0.016 0.29
      bd143a 54968 -0.05 0.12 -0.012 0.22
      bh159a 54955 0.00 0.13 -0.012 0.22
      bi037f 54971 -0.04 0.14 0.008 0.19
      bk145a 54974 -0.07 0.11 -0.006 0.16
      bk145b 54975 -0.06 0.14 -0.016 0.28
      bk145c 54976 -0.05 0.16 -0.011 0.24
      bk150j 54966 -0.07 0.03 -0.003 0.09
      bl149bk 54954 -0.04 0.08 -0.018 0.28
      bl149bl 54980 -0.08 0.06 0.013 0.22
      bm272hb 54958 -0.05 0.10 -0.006 0.14
      bm272hc 54965 -0.10 0.17 0.004 0.21
      bm272ib 54959 -0.05 0.10 0.004 0.13
      bm286d 54970 -0.12 0.14 0.012 0.26
      bm296 54983 -0.04 0.10 -0.006 0.14
      bm307 54969 -0.02 0.12 -0.008 0.17
      bm308a 54980 -0.08 0.06 0.013 0.22
      bm308b 54982 -0.08 0.11 -0.015 0.26
      bp150ad 54973 -0.08 0.18 0.003 0.20
      br138a 54956 -0.10 0.08 -0.010 0.20
      bs193d 54979 -0.11 0.11 0.017 0.30
      bt097f 54968 -0.04 0.14 -0.010 0.21
      bz036e 54955 0.00 0.13 -0.012 0.22
      bb240ca 54989 -0.05 0.09 -0.014 0.23
      bb240cb 54997 -0.09 0.15 -0.014 0.27
      bb240cc 55003 -0.09 0.19 -0.021 0.38
      bb240cd 55010 -0.11 0.19 -0.015 0.31
      bb273 54995 -0.09 0.17 0.000 0.19
      bd143b 54995 -0.09 0.17 0.000 0.19
      bf092cd 54990 -0.07 0.13 -0.012 0.23
      bf094a 55012 -0.06 0.32 0.001 0.33
      bj067a 55007 -0.04 0.10 0.007 0.15
      bj068d 54991 -0.06 0.14 -0.001 0.15
      bk150k 54984 -0.03 0.12 -0.004 0.14
      bk150l 55003 -0.09 0.20 -0.020 0.37
      bl149bm 54986 -0.09 0.11 -0.005 0.16
      bl149bn 54998 -0.04 0.20 0.003 0.21
      bl149bo 55008 -0.10 0.23 0.011 0.30
      bl160e 54986 -0.09 0.11 -0.006 0.17
      bm305 55010 -0.11 0.19 -0.015 0.31
      bm308c 54985 -0.10 0.14 -0.011 0.24
      bm308d 54988 -0.10 0.10 -0.017 0.29
      bm308e 54989 -0.05 0.09 -0.014 0.23
      bm308f 54991 -0.06 0.14 -0.001 0.15
      bm308g 54992 -0.14 0.16 0.006 0.23
      bm308h 54994 -0.07 0.15 0.007 0.20
      bm308i 54996 -0.07 0.15 -0.012 0.24
      bm308j 54998 -0.04 0.20 0.003 0.21
      br148a 55011 -0.06 0.14 -0.013 0.25
      bs194a 55011 -0.06 0.14 -0.013 0.25
      by127 55002 -0.07 0.17 -0.005 0.20
      bb240ce 55020 -0.03 0.15 -0.001 0.15
      bb240cg 55035 -0.05 0.14 -0.001 0.15
      bb268a 55032 -0.05 0.11 -0.010 0.19
      bf094b 55015 -0.06 0.17 0.004 0.19
      bf094c 55016 -0.06 0.20 -0.011 0.27
      bf094d 55022 -0.07 0.23 -0.004 0.25
      bh159b 55038 -0.10 0.16 -0.008 0.22
      bl149bp 55018 -0.07 0.16 -0.018 0.32
      bl149bq 55036 -0.03 0.15 -0.027 0.43
      bm290d 55016 -0.06 0.20 -0.011 0.27
      bm295 55027 -0.02 0.17 0.011 0.24
      bm308k 55022 -0.07 0.23 -0.004 0.25
      bm308l 55024 -0.07 0.16 -0.013 0.26
      bm308m 55025 -0.02 0.15 -0.004 0.16
      bm308n 55031 -0.08 0.14 -0.021 0.35
      bm308o 55033 -0.04 0.15 0.003 0.16
      bp146d 55015 -0.06 0.17 0.004 0.19
      bp150ae 55034 -0.11 0.26 0.000 0.28
      bp159a 55018 -0.07 0.16 -0.017 0.31
      bp159b 55030 -0.05 0.15 -0.001 0.16
      br141c 55026 -0.27 0.13 0.008 0.32
      bs194b 55040 -0.03 0.21 -0.026 0.44
      bb240ci 55052 -0.04 0.12 -0.008 0.17
      bb240cj 55057 0.01 0.12 -0.005 0.14
      bb240ck 55065 -0.09 0.13 0.009 0.21
      bb240cl 55073 -0.05 0.12 -0.006 0.16
      bb268b 55046 -0.07 0.16 -0.024 0.40
      bb269b 55045 -0.05 0.19 -0.018 0.33
      bb271a 55067 -0.13 0.16 -0.014 0.29
      bb271b 55071 -0.08 0.13 -0.005 0.17
      bc186d 55066 -0.07 0.12 -0.004 0.15
      bd142a 55075 -0.06 0.16 -0.007 0.20
      bk153a 55062 -0.08 0.14 0.009 0.21
      bl149br 55063 -0.08 0.16 0.004 0.19
      bl160f 55075 -0.18 0.29 0.015 0.41
      bm303a 55060 -0.06 0.16 -0.005 0.19
      bm308p 55050 -0.05 0.12 -0.007 0.17
      bp157b 55065 -0.09 0.12 0.008 0.19
      bs194c 55070 -0.07 0.11 0.004 0.14
      bb240cm 55079 -0.05 0.17 -0.007 0.21
      bb240cn 55082 -0.08 0.16 -0.003 0.18
      bb240co 55093 -0.12 0.22 -0.004 0.26
      bb240cp 55101 -0.06 0.21 -0.053 0.82
      bb276a 55105 -0.12 0.20 0.001 0.23
      bj068e 55089 -0.04 0.17 0.002 0.18
      bk159a 55080 -0.03 0.16 -0.007 0.19
      bk159b 55086 -0.10 0.20 -0.005 0.24
      bm257g 55077 -0.01 0.17 0.015 0.28
      bm257h 55099 -0.14 0.21 -0.011 0.30
      bm303b 55091 -0.08 0.16 0.003 0.18
      bm306 55102 0.02 0.14 -0.038 0.59
      bp150af 55095 -0.10 0.19 -0.009 0.25
      bp157c 55090 -0.11 0.17 0.006 0.22
      bz039a 55092 0.01 0.18 -0.008 0.22
      bb240cq 55110 0.07 0.21 0.022 0.40
      bb240cr 55131 -0.02 0.09 -0.006 0.13
      bb240cv 55110 0.07 0.21 0.022 0.40
      bb277aa 55107 -0.12 0.20 -0.006 0.25
      bb277ab 55107 -0.04 0.09 -0.007 0.14
      bb277ac 55107 -0.12 0.20 -0.006 0.25
      bb277ad 55107 -0.04 0.09 -0.007 0.14
      bb277ae 55107 -0.12 0.20 -0.007 0.26
      bb277b 55109 -0.08 0.20 -0.001 0.22
      bc188c 55124 -0.13 0.22 0.001 0.26
      bg197a 55122 -0.05 0.14 -0.009 0.20
      bl149cb 55108 -0.08 0.23 -0.006 0.26
      bl149cc 55132 -0.04 0.10 0.003 0.12
      bl155i 55130 0.00 0.21 0.010 0.26
      bl168a 55119 -0.16 0.17 0.016 0.33
      bl168b 55124 -0.10 0.11 -0.014 0.26
      bm272je 55127 -0.04 0.10 0.000 0.11
      bm272jf 55128 -0.11 0.20 0.005 0.24
      bm303c 55121 -0.04 0.09 -0.009 0.17
      bm311 55112 -0.16 0.20 0.016 0.35
      bp157d 55120 -0.06 0.09 0.004 0.12
      bp157e 55122 -0.05 0.14 -0.009 0.20
      br129ae 55128 -0.11 0.20 0.006 0.25
      br134ad 55123 -0.04 0.22 -0.010 0.27
      br134bd 55125 0.00 0.21 0.008 0.24
      br141d 55136 -0.09 0.17 -0.004 0.20
      bs194d 55106 -0.09 0.11 0.000 0.14
      bb240cs 55138 -0.05 0.12 0.000 0.13
      bb240ct 55141 -0.05 0.05 -0.001 0.07
      bb240cu 55153 0.01 0.16 0.003 0.17
      bb240cw 55158 -0.08 0.18 0.002 0.20
      bb261k 55161 -0.08 0.14 0.001 0.16
      bb261l 55165 -0.02 0.15 -0.006 0.18
      bc188d 55145 -0.04 0.17 0.002 0.18
      bd142b 55149 -0.11 0.15 -0.007 0.21
      bd143c 55157 -0.11 0.16 -0.005 0.21
      bh159c 55146 -0.14 0.12 0.001 0.19
      bm257i 55137 -0.13 0.21 0.011 0.30
      bm257j 55139 -0.11 0.22 -0.001 0.25
      bm272hd 55149 -0.08 0.03 -0.001 0.09
      bm272ic 55150 -0.09 0.14 -0.003 0.17
      bm290e 55157 -0.09 0.10 -0.005 0.15
      bm303d 55164 -0.07 0.13 0.003 0.15
      bm308q 55155 -0.24 0.20 0.005 0.32
      bm308r 55157 -0.09 0.10 -0.005 0.15
      bm308s 55158 -0.08 0.18 0.002 0.20
      bm308t 55161 -0.08 0.14 0.001 0.16
      bm308u 55163 -0.09 0.13 0.004 0.17
      bs194e 55143 -0.11 0.12 -0.010 0.22
      bs194f 55166 -0.17 0.28 0.005 0.34
      bb240cx 55170 -0.07 0.15 0.000 0.17
      bb240cy 55178 -0.06 0.17 0.011 0.24
      bb240da 55193 -0.12 0.12 -0.004 0.18
      bb261m 55172 -0.05 0.18 -0.009 0.23
      bb261n 55188 -0.11 0.13 0.019 0.33
      bb276b 55173 -0.10 0.32 0.006 0.35
      bb277c 55170 -0.07 0.15 0.000 0.17
      be055b 55185 -0.07 0.09 -0.011 0.20
      be056c 55189 -0.14 0.13 0.002 0.19
      bh164 55168 -0.11 0.13 0.001 0.17
      bj068f 55177 -0.08 0.14 0.003 0.17
      bk159d 55195 -0.08 0.19 0.002 0.21
      bl149cd 55176 -0.12 0.04 0.004 0.14
      bl149ce 55183 -0.02 -0.01 0.012 0.18
      bl149cf 55192 -0.09 0.13 -0.006 0.18
      bl160g 55171 -0.07 0.16 0.001 0.18
      bm272ie 55186 -0.12 0.14 -0.005 0.20
      bm308v 55174 -0.06 0.17 0.003 0.19
      bm308w 55179 -0.06 0.19 0.006 0.22
      bm308x 55196 -0.13 0.14 0.010 0.24
      bm316 55184 -0.16 0.12 -0.004 0.21
      bm331a 55182 0.06 0.12 0.002 0.14
      bm331b 55185 -0.07 0.13 -0.011 0.22
      bm331c 55188 -0.11 0.13 0.019 0.33
      bm331d 55190 -0.12 0.12 -0.004 0.18
      br146a 55179 -0.06 0.19 0.006 0.22
      bs194g 55194 -0.03 0.11 -0.008 0.17
      bs196a 55176 -0.09 0.09 0.005 0.15
      bs196c 55174 -0.06 0.17 0.003 0.19
      ----------------------------------------------------
      Maximum difference between used and final EOPs:
      XPOLE: 0.37 mas; YPOLE: 0.32 mas; UT1-UTC: 0.053 milliseconds; combined: 0.82 mas.

      From 307 projects, 61 (12) have differences larger than 0.10 (0.15) mas in XPOLE.
      From 307 projects, 249 (125) have differences larger than 0.10 (0.15) mas in YPOLE.
      From 307 projects, 96 (5) have differences larger than 10 (30) microseconds in UT1-UTC.

      

      EOP difference 2010

      by Amy Mioduszewski last modified Aug 18, 2011
      Difference in EOPs from correlation and the best USNO numbers from all the experiments in 2010.
        Obs     MJD    diff X   diff Y  diff UT1  combined
      [mas] [mas] [ms] [mas]
      ----------------------------------------------------
      bb240db 55206 -0.11 0.14 -0.009 0.22
      bb240dc 55212 -0.10 0.13 -0.006 0.19
      bb240dd 55226 -0.11 0.16 -0.005 0.21
      bb261p 55210 -0.12 0.15 0.004 0.20
      bb261q 55212 -0.10 0.13 -0.006 0.19
      bb261r 55223 -0.06 0.13 0.001 0.14
      bd142c 55228 -0.08 0.11 -0.020 0.33
      bd149a 55223 -0.06 0.13 0.001 0.14
      be055a 55198 -0.12 0.12 0.004 0.18
      bh159d 55221 -0.06 0.10 -0.014 0.24
      bj071 55227 -0.10 0.10 -0.004 0.15
      bk159c 55200 -0.07 0.12 0.002 0.14
      bl149cg 55213 -0.11 0.12 0.002 0.17
      bl168c 55206 -0.11 0.14 -0.009 0.22
      bm303e 55207 -0.15 0.09 -0.011 0.24
      bm308aa 55211 -0.14 0.17 0.006 0.24
      bm308ab 55213 -0.11 0.12 0.001 0.16
      bm308ac 55218 -0.17 0.15 -0.009 0.26
      bm308y 55199 -0.11 0.13 -0.003 0.18
      bm308z 55210 -0.12 0.15 0.004 0.20
      bm310a 55203 -0.14 0.13 0.017 0.32
      bm310b 55204 0.07 0.10 0.014 0.24
      br141e 55222 -0.20 0.23 -0.020 0.43
      br145a2 55204 0.07 0.10 0.014 0.24
      br145a3 55227 -0.10 0.10 -0.004 0.15
      br145a4 55211 -0.14 0.17 0.006 0.24
      br145a5 55221 -0.06 0.10 -0.014 0.24
      br145ad 55215 -0.09 0.13 -0.014 0.26
      br145af 55223 -0.06 0.13 0.001 0.14
      br145ag 55218 -0.17 0.15 -0.009 0.26
      br145aj 55209 -0.10 0.13 0.006 0.19
      bs196b 55199 -0.11 0.13 -0.003 0.18
      bs196d 55208 -0.12 0.25 0.012 0.33
      bw093a 55214 -0.09 0.11 -0.008 0.19
      bb240de 55229 -0.12 0.13 -0.006 0.20
      bb240dg 55242 -0.11 0.12 -0.010 0.22
      bb274a 55232 -0.11 0.14 -0.010 0.23
      bb277d 55233 -0.12 0.15 -0.013 0.27
      bb278a 55241 -0.13 0.12 -0.016 0.30
      bb278b 55240 -0.15 0.15 -0.007 0.24
      bb280a 55249 -0.11 0.10 -0.006 0.17
      bb280b 55246 -0.12 0.14 0.000 0.18
      bb280c 55249 -0.11 0.10 -0.006 0.17
      bb280d 55246 -0.12 0.14 0.000 0.18
      bb280e 55253 -0.14 0.14 -0.028 0.46
      bb280f 55255 -0.11 0.09 -0.003 0.15
      bb290a 55246 -0.12 0.14 0.000 0.18
      bb290b 55251 -0.15 0.14 -0.003 0.21
      bb290c 55254 -0.15 0.10 -0.013 0.27
      bd146a 55255 -0.11 0.09 -0.003 0.15
      bd146b 55256 -0.10 0.10 -0.005 0.16
      bd147a 55242 -0.11 0.12 -0.010 0.22
      bd147b 55247 -0.13 0.11 -0.007 0.20
      be055c 55243 -0.13 0.11 0.000 0.17
      be056a 55233 -0.09 0.05 -0.009 0.17
      bg197b 55252 -0.16 0.15 -0.006 0.24
      bg199a 55248 -0.12 0.11 -0.003 0.17
      bl149ch 55239 -0.10 0.10 -0.003 0.15
      bm303f 55238 -0.17 0.15 0.007 0.25
      bm317 55234 -0.12 0.15 -0.014 0.28
      bm319a 55253 -0.13 0.14 -0.009 0.23
      bm319b 55254 -0.15 0.10 -0.002 0.18
      bm319c 55255 -0.11 0.09 -0.002 0.15
      bm319d 55256 -0.10 0.10 -0.005 0.16
      bm323a 55251 -0.15 0.14 -0.003 0.21
      br145a6 55238 -0.17 0.15 0.007 0.25
      br145a7 55241 -0.13 0.12 -0.016 0.30
      br145a8 55247 -0.13 0.11 -0.007 0.20
      br145a9 55248 -0.12 0.11 -0.003 0.17
      br145aa 55246 -0.12 0.14 0.000 0.18
      br145ah 55252 -0.17 0.15 -0.006 0.24
      br145aq 55237 -0.14 0.15 0.006 0.22
      bs194i 55243 -0.13 0.11 0.000 0.17
      bb240dh 55258 -0.13 0.09 -0.007 0.19
      bb240di 55271 -0.13 0.10 -0.015 0.28
      bb240dj 55275 -0.18 0.08 -0.003 0.20
      bb240dk 55283 -0.19 0.09 -0.005 0.22
      bb240dl 55284 -0.16 0.10 -0.004 0.20
      bd146c 55257 -0.11 0.14 -0.023 0.39
      bd147c 55259 -0.13 0.08 -0.005 0.17
      bd147d 55256 -0.10 0.10 -0.005 0.16
      bf100a 55273 -0.14 0.09 -0.003 0.17
      bf100b 55281 -0.17 0.09 -0.008 0.23
      bk159e 55284 -0.16 0.10 -0.004 0.20
      bl149ci 55266 -0.13 0.12 -0.007 0.21
      bl160h 55268 -0.11 0.11 -0.009 0.21
      bl169a 55284 -0.16 0.10 -0.004 0.20
      bl170a 55285 -0.14 0.12 -0.006 0.21
      bm303g 55262 -0.15 0.10 -0.020 0.35
      bm319e 55257 -0.11 0.14 -0.024 0.40
      bm319f 55258 -0.13 0.09 -0.008 0.20
      bm319g 55259 -0.13 0.08 -0.005 0.17
      bm321a 55268 -0.11 0.11 -0.009 0.21
      bm326 55285 -0.14 0.12 -0.006 0.21
      bn041 55282 -0.17 0.06 -0.009 0.23
      br145ac 55259 -0.13 0.08 -0.005 0.17
      br145ae 55264 -0.19 0.12 0.007 0.25
      br145ai 55276 -0.15 0.07 0.000 0.17
      br145am 55285 -0.14 0.12 -0.006 0.21
      br145b1 55269 -0.10 0.06 -0.002 0.12
      br146b 55270 -0.11 0.11 -0.003 0.16
      bv069a 55285 -0.14 0.12 -0.006 0.21
      bv069b 55286 -0.16 0.12 -0.008 0.23
      bw091b 55286 -0.09 0.04 -0.007 0.14
      gb071a 55276 -0.08 0.04 -0.009 0.16
      bb240dm 55288 -0.09 0.04 0.002 0.10
      bb240dn 55297 -0.14 0.09 -0.005 0.18
      bb240do 55306 -0.10 0.15 -0.008 0.22
      bb240dp 55315 -0.14 0.12 -0.009 0.23
      bb261s 55299 -0.04 0.13 0.015 0.26
      bb278i 55289 -0.16 0.12 -0.005 0.21
      bb278j 55292 -0.14 0.11 -0.004 0.19
      bb291a 55311 -0.11 0.15 -0.010 0.24
      bb291b 55315 -0.14 0.12 -0.010 0.24
      bd150 55314 -0.15 0.11 -0.014 0.28
      bf100c 55291 -0.10 0.14 0.000 0.17
      bf100i 55312 -0.07 0.13 -0.005 0.17
      bg187a 55291 -0.11 0.14 -0.002 0.18
      bh163a 55294 -0.15 0.08 0.001 0.17
      bh163b 55304 -0.11 0.12 -0.008 0.20
      bk166b 55289 -0.16 0.12 -0.005 0.21
      bk166c 55293 -0.15 0.12 0.000 0.19
      bk166d 55297 -0.14 0.09 -0.005 0.18
      bk166e 55302 -0.15 0.17 -0.007 0.25
      bk166f 55308 -0.10 0.15 -0.004 0.19
      bk166g 55316 -0.13 0.15 -0.013 0.28
      bl169b 55290 -0.07 0.09 -0.004 0.13
      bl169c 55298 -0.13 0.11 -0.005 0.19
      bm272jg 55308 -0.10 0.15 -0.004 0.19
      bm272jh 55309 -0.13 0.13 -0.009 0.23
      bm308ad 55309 -0.13 0.13 -0.008 0.22
      bm308ae 55310 -0.16 0.13 -0.006 0.22
      bm308af 55312 -0.07 0.13 -0.005 0.17
      bm308ag 55317 -0.14 0.13 -0.006 0.21
      bm327 55288 -0.13 0.11 0.003 0.18
      br145an 55302 -0.15 0.17 -0.007 0.25
      br145ao 55313 -0.07 0.13 -0.014 0.26
      br145b2 55290 -0.12 0.14 -0.004 0.19
      br145b3 55316 -0.13 0.15 -0.013 0.28
      br145c1 55295 -0.12 0.16 -0.014 0.29
      br145c2 55299 -0.04 0.13 0.015 0.26
      br145c3 55303 -0.13 0.11 -0.002 0.17
      br145d1 55311 -0.11 0.15 -0.010 0.24
      br145g1 55310 -0.16 0.13 -0.006 0.22
      br145h1 55303 -0.13 0.11 -0.002 0.17
      bv069c 55289 -0.16 0.12 -0.005 0.21
      bv069d 55293 -0.15 0.12 0.000 0.19
      bw093b 55290 -0.07 0.09 -0.004 0.13
      bw093c 55305 -0.10 0.14 -0.006 0.19
      bw093d 55317 -0.14 0.13 -0.006 0.21
      bb240dq 55322 -0.12 0.14 -0.009 0.23
      bb240dr 55333 -0.15 0.13 -0.009 0.24
      bb240ds 55337 -0.14 0.12 -0.007 0.21
      bb240dt 55344 -0.12 0.14 -0.012 0.26
      bb274b 55334 -0.15 0.13 0.006 0.22
      bb277e 55321 -0.12 0.15 -0.007 0.22
      bb281a 55346 -0.08 0.11 -0.003 0.14
      bb282 55334 -0.15 0.13 0.006 0.22
      bc188e 55318 -0.10 0.12 -0.005 0.17
      bd148c 55339 -0.10 0.10 -0.003 0.15
      be056b 55348 -0.11 0.13 -0.006 0.19
      bf100d 55343 -0.14 0.17 0.014 0.30
      bk163a 55339 -0.12 0.15 -0.002 0.19
      bk166h 55321 -0.12 0.15 -0.006 0.21
      bk166i 55330 -0.13 0.16 -0.012 0.27
      bk166j 55338 -0.14 0.14 -0.004 0.21
      bl170b 55337 -0.14 0.12 -0.007 0.21
      bl170d 55344 -0.12 0.14 -0.012 0.26
      bm272id 55322 -0.12 0.14 -0.009 0.23
      bm303h 55336 -0.10 0.15 -0.005 0.20
      bm308ah 55319 -0.08 0.10 -0.006 0.16
      bm308ai 55323 -0.09 0.11 -0.009 0.20
      br138b 55320 -0.13 0.14 -0.003 0.20
      br145ab 55347 -0.09 0.16 -0.005 0.20
      br145ap 55328 -0.14 0.10 -0.009 0.22
      br145ar 55337 -0.14 0.12 -0.007 0.21
      br145e1 55333 -0.15 0.13 -0.009 0.24
      bs198a 55343 -0.14 0.17 0.014 0.30
      bt107 55345 -0.09 0.08 -0.010 0.19
      bw093e 55332 -0.15 0.12 -0.007 0.22
      bw093f 55347 -0.09 0.16 -0.005 0.20
      bz039b 55322 -0.12 0.14 -0.009 0.23
      bz039c 55319 -0.08 0.10 -0.006 0.16
      gb071b 55346 -0.09 0.12 -0.002 0.15
      bb240du 55352 -0.12 0.15 -0.005 0.21
      bb240dv 55360 -0.13 0.10 -0.007 0.19
      bb240dw 55366 -0.07 0.00 -0.009 0.15
      bb287a 55359 -0.10 0.07 -0.008 0.17
      bb287b 55373 -0.12 0.07 -0.004 0.15
      bd137 55373 -0.12 0.07 -0.001 0.14
      bf100e 55372 -0.10 0.05 0.000 0.11
      bg187b 55359 -0.10 0.07 -0.010 0.19
      bg199b 55358 -0.14 0.08 -0.009 0.21
      bg204a 55349 -0.12 0.11 -0.006 0.19
      bl149ck 55367 -0.09 0.03 -0.005 0.12
      bl160i 55356 -0.11 0.08 0.007 0.17
      bl170c 55352 -0.12 0.15 -0.005 0.21
      bm303i 55362 -0.13 0.12 -0.007 0.21
      bm346 55364 -0.11 0.08 -0.008 0.18
      bm347 55369 -0.10 0.06 -0.003 0.12
      br145ak 55349 -0.12 0.11 -0.006 0.19
      br145al 55355 -0.09 0.06 0.025 0.39
      br145as 55360 -0.13 0.10 -0.007 0.19
      br145at 55354 -0.12 0.12 0.004 0.18
      br145au 55357 -0.12 0.08 0.000 0.14
      br145av 55361 -0.13 0.09 -0.006 0.18
      br145f1 55353 -0.12 0.16 0.003 0.21
      br145g2 55368 -0.11 0.06 0.002 0.13
      br145h2 55365 -0.09 0.09 -0.017 0.28
      br146c 55369 -0.10 0.06 -0.003 0.12
      bt108 55353 -0.12 0.16 0.003 0.21
      bt110a 55378 -0.10 0.08 0.008 0.18
      by128a 55378 -0.10 0.08 0.007 0.17
      gb071c 55355 -0.07 0.02 -0.002 0.08
      ba095 55383 -0.09 0.07 -0.003 0.12
      ba097 55382 -0.10 0.09 -0.002 0.14
      bb240dx 55386 -0.09 0.10 -0.013 0.24
      bb240dy 55384 -0.08 0.13 -0.013 0.25
      bb240dz 55393 -0.09 -0.02 -0.002 0.10
      bb240ea 55398 -0.10 0.10 0.001 0.14
      bb240eb 55408 -0.10 0.10 0.009 0.20
      bb274c 55379 -0.06 0.00 -0.001 0.06
      bb274d 55397 -0.10 0.14 0.016 0.30
      bb274e 55402 -0.10 0.09 -0.013 0.24
      bb277f 55380 -0.04 -0.02 -0.005 0.09
      bc191a 55393 -0.06 0.12 0.024 0.38
      bc191b 55398 -0.10 0.10 0.001 0.14
      bd149b 55381 -0.10 0.10 -0.009 0.20
      bd149c 55395 -0.08 0.04 0.009 0.16
      bg202 55388 -0.08 0.09 -0.010 0.19
      bk163c 55384 -0.08 0.13 -0.013 0.25
      bl149cl 55390 -0.12 0.06 0.001 0.14
      bl174a 55404 -0.12 0.13 0.020 0.35
      bl174b 55408 -0.10 0.10 0.009 0.20
      bm332c 55394 -0.02 -0.02 -0.005 0.08
      bm335a 55400 -0.09 0.07 0.009 0.18
      bm335b 55401 -0.11 0.09 -0.015 0.27
      br145aw 55378 -0.10 0.08 0.007 0.17
      br145d2 55403 -0.10 0.12 0.007 0.19
      br159a 55392 -0.09 0.10 0.004 0.15
      br159b 55394 -0.02 -0.02 -0.006 0.09
      br159c 55396 -0.10 0.09 0.008 0.18
      br159d 55399 -0.10 0.09 0.002 0.14
      br159e 55389 -0.08 0.08 -0.007 0.15
      bt110b 55381 -0.10 0.10 -0.009 0.20
      bt110c 55389 -0.08 0.08 -0.007 0.15
      bt110d 55407 -0.11 0.12 0.017 0.30
      bb240ec 55414 -0.07 0.04 -0.002 0.09
      bb240ed 55418 -0.10 0.10 0.016 0.28
      bb240ee 55429 -0.07 0.09 0.000 0.11
      bb240ef 55435 -0.07 0.09 -0.033 0.51
      bc170ca 55431 -0.07 0.08 -0.006 0.14
      bc191c 55411 -0.07 0.09 0.010 0.19
      bc191d 55418 -0.10 0.10 0.016 0.28
      bc191e 55420 -0.11 0.13 -0.005 0.19
      bc191f 55420 -0.11 0.13 -0.005 0.19
      bc191g 55428 -0.06 0.09 0.001 0.11
      bc191h 55429 -0.07 0.09 0.000 0.11
      bc191i 55437 -0.08 0.05 -0.018 0.29
      bc192 55421 -0.07 0.14 0.013 0.25
      bg204c 55438 -0.08 0.09 -0.016 0.27
      bk163d 55416 -0.09 0.09 0.002 0.13
      bl149cm 55415 -0.11 0.08 -0.006 0.16
      bl149cn 55436 -0.10 0.07 -0.022 0.35
      bm303j 55410 -0.09 0.10 -0.003 0.14
      bm303k 55430 -0.08 0.08 0.007 0.15
      bm321b 55423 -0.05 0.00 -0.005 0.09
      bm321c 55429 -0.04 -0.01 0.001 0.04
      bp161a 55420 -0.11 0.13 -0.005 0.19
      br145ax 55428 -0.06 0.09 0.001 0.11
      br145ay 55433 -0.11 0.08 -0.027 0.43
      br145az 55438 -0.08 0.09 -0.016 0.27
      br145e2 55417 -0.12 0.11 0.006 0.19
      br145g3 55432 -0.05 0.08 -0.038 0.58
      br145h3 55424 -0.08 0.09 0.012 0.22
      bb240eg 55444 -0.10 0.09 -0.015 0.26
      bb240eh 55447 -0.10 0.09 -0.009 0.19
      bb240ei 55459 -0.12 0.11 -0.026 0.42
      bb240ej 55466 -0.16 0.10 -0.018 0.33
      bb277g 55445 -0.06 0.10 -0.037 0.57
      bc191j 55446 -0.08 0.10 -0.039 0.60
      bc191k 55451 -0.11 0.11 -0.027 0.43
      bc191l 55453 -0.10 0.07 -0.005 0.14
      bc191m 55455 -0.12 0.07 -0.007 0.17
      bg204b 55441 -0.08 0.12 -0.021 0.35
      bj067b 55448 -0.07 0.10 -0.009 0.18
      bk163b 55446 -0.08 0.10 -0.039 0.60
      bk163e 55447 -0.10 0.09 -0.009 0.19
      bl149cp 55457 -0.09 0.07 -0.015 0.25
      bl149cq 55467 -0.14 0.07 -0.008 0.20
      bl149cr 55469 -0.11 0.11 -0.007 0.19
      bl160j 55442 -0.10 0.09 -0.005 0.15
      bl176a 55452 -0.09 0.13 -0.018 0.31
      bm303l 55458 -0.13 0.10 -0.020 0.34
      br145b4 55444 -0.10 0.09 -0.018 0.30
      br145b5 55452 -0.09 0.13 -0.018 0.31
      br145c4 55451 -0.11 0.11 -0.027 0.43
      br145c5 55465 -0.13 0.10 -0.014 0.27
      br145d3 55464 -0.11 0.07 -0.014 0.25
      br145f2 55441 -0.08 0.12 -0.021 0.35
      br145g4 55465 -0.13 0.10 -0.014 0.27
      br145h4 55464 -0.11 0.07 -0.014 0.25
      br145i1 55459 -0.12 0.11 -0.026 0.42
      br145r1 55450 -0.07 0.12 -0.037 0.57
      br145u1 55460 -0.13 0.07 -0.033 0.52
      by128b 55470 -0.14 0.05 -0.033 0.52
      bz039d 55455 -0.12 0.07 -0.008 0.18
      bb240ek 55471 -0.11 0.06 0.003 0.13
      bb240el 55477 -0.11 0.12 -0.004 0.17
      bb240em 55486 -0.13 0.09 -0.002 0.16
      bb240en 55501 -0.08 0.15 -0.007 0.20
      bb286a 55498 -0.09 0.17 -0.009 0.24
      bb286b 55499 -0.09 0.14 0.000 0.17
      bb286c 55500 -0.08 0.13 0.000 0.15
      bb295 55488 -0.11 0.08 0.015 0.26
      bc191n 55493 -0.13 0.13 -0.013 0.27
      bc192b 55486 -0.13 0.09 -0.002 0.16
      bh167 55492 -0.09 0.10 -0.010 0.20
      bl149cs 55485 -0.17 0.09 -0.011 0.25
      bl149ct 55495 -0.15 0.11 -0.011 0.25
      bm272ji 55489 -0.10 0.09 0.008 0.18
      bm303m 55494 -0.15 0.14 -0.024 0.41
      bm335c 55487 -0.13 0.10 0.000 0.16
      br145b6 55473 -0.10 0.10 -0.002 0.14
      br145b7 55493 -0.13 0.13 -0.013 0.27
      br145b8 55498 -0.08 0.17 -0.010 0.24
      br145c6 55471 -0.11 0.06 -0.019 0.31
      br145c7 55499 -0.10 0.14 0.001 0.17
      br145e3 55481 -0.12 0.10 -0.008 0.20
      br145i7 55492 -0.09 0.10 -0.006 0.16
      br145k1 55477 -0.11 0.12 -0.004 0.17
      bv070a 55472 -0.14 0.09 0.002 0.17
      bv070b 55476 -0.11 0.12 -0.001 0.16
      bv070c 55484 -0.15 0.10 -0.025 0.42
      bv070d 55489 -0.10 0.09 0.008 0.18
      bw094a 55484 -0.15 0.10 -0.025 0.42
      bw094b 55499 -0.10 0.14 0.001 0.17
      bb240eo 55508 -0.09 0.09 -0.013 0.23
      bb240ep 55520 -0.06 0.11 -0.007 0.16
      bb240eq 55525 -0.06 0.12 -0.016 0.27
      bb278k 55522 -0.06 0.00 0.007 0.12
      bb278l 55529 -0.09 0.12 -0.001 0.15
      bb293a 55519 -0.06 0.12 0.002 0.14
      bc170cc 55531 -0.02 0.00 -0.004 0.06
      bd152a0 55525 -0.06 0.12 -0.016 0.27
      bd152a1 55506 -0.09 0.16 -0.006 0.20
      bd152a3 55517 -0.06 0.13 0.011 0.22
      bd152a4 55507 -0.12 0.10 -0.002 0.16
      bd152a5 55513 -0.13 0.12 0.002 0.18
      bd152ac 55523 -0.11 0.14 0.012 0.25
      bd152ad 55513 -0.13 0.12 0.002 0.18
      bf100f 55504 -0.10 0.11 -0.004 0.16
      bh172a 55527 -0.12 0.13 -0.007 0.21
      bl149cv 55505 -0.07 0.13 0.001 0.15
      bl149cw 55514 -0.09 0.12 0.002 0.15
      bl149cx 55521 -0.07 0.09 -0.008 0.17
      bl149cy 55530 -0.07 0.11 0.010 0.20
      br145b9 55516 -0.09 0.09 0.010 0.20
      br145c8 55515 -0.07 0.10 0.002 0.13
      br145c9 55524 -0.07 0.12 -0.015 0.26
      br145d4 55519 -0.06 0.12 0.002 0.14
      br145e4 55528 -0.13 0.11 -0.004 0.18
      br145f3 55527 -0.12 0.13 -0.008 0.21
      br145g5 55516 -0.09 0.09 0.010 0.20
      br145h5 55515 -0.07 0.10 0.002 0.13
      bs206i 55512 -0.12 0.11 0.001 0.16
      bw094c 55513 -0.13 0.12 0.002 0.18
      bw094d 55527 -0.12 0.13 -0.008 0.21
      gc034b 55509 -0.09 0.08 -0.029 0.45
      gc034c 55511 -0.10 0.15 -0.004 0.19
      gc034d 55512 0.11 0.03 -0.003 0.12
      bb240er 55534 -0.10 0.10 0.004 0.15
      bb240es 55537 -0.07 0.06 -0.008 0.15
      bb240et 55548 -0.12 0.10 0.004 0.17
      bb240eu 55553 -0.11 0.13 0.006 0.19
      bb240ev 55560 -0.12 0.12 0.039 0.61
      bb278m 55561 -0.07 0.01 0.014 0.22
      bc191o 55542 -0.08 0.10 -0.008 0.18
      bc191p 55542 -0.08 0.10 -0.008 0.18
      bc191q 55549 -0.11 0.07 -0.003 0.14
      bc191r 55551 -0.17 0.10 0.011 0.26
      bd152a2 55551 -0.17 0.10 0.011 0.26
      bd152a8 55531 -0.16 0.09 -0.001 0.18
      bd152a9 55545 -0.12 0.08 0.000 0.14
      bd152aa 55531 -0.16 0.09 -0.001 0.18
      bd152ab 55549 -0.11 0.07 -0.003 0.14
      bd152ae 55542 -0.08 0.10 -0.008 0.18
      bd152af 55559 -0.12 0.08 0.011 0.22
      bd152ah 55553 -0.11 0.13 0.006 0.19
      bd152b4 55553 -0.11 0.13 0.006 0.19
      be057a 55559 -0.12 0.09 0.012 0.23
      bh172b 55547 -0.16 0.14 0.001 0.21
      bl149cz 55555 -0.05 -0.01 0.001 0.05
      bm300 55549 -0.11 0.07 -0.003 0.14
      bm303n 55535 -0.10 0.10 0.007 0.18
      bm333 55538 -0.09 0.10 0.001 0.14
      bm341 55545 -0.12 0.08 0.000 0.14
      bo038a 55561 -0.10 0.13 0.014 0.27
      br145d5 55547 -0.16 0.14 0.001 0.21
      br145e5 55562 -0.11 0.09 -0.002 0.15
      br145f4 55543 -0.08 0.11 0.007 0.17
      br145i2 55550 -0.13 0.13 -0.005 0.20
      br145r2 55545 -0.12 0.08 0.000 0.14
      br145u2 55554 -0.06 0.03 0.008 0.14
      br145v1 55541 -0.10 0.07 -0.013 0.23
      br152a 55544 -0.15 0.07 -0.007 0.20
      bs205 55544 -0.15 0.07 -0.007 0.20
      bs206a 55541 -0.10 0.07 -0.013 0.23
      bs206b 55551 -0.17 0.10 0.010 0.25
      bs206e 55539 -0.13 0.12 -0.007 0.21
      bw094e 55541 -0.10 0.07 -0.013 0.23
      bw094f 55554 -0.10 0.11 0.011 0.22
      ----------------------------------------------------
      Maximum difference between used and final EOPs:
      XPOLE: 0.2 mas; YPOLE: 0.25 mas; UT1-UTC: 0.039 milliseconds; combined: 0.61 mas.

      From 412 projects, 262 (42) have differences larger than 0.10 (0.15) mas in XPOLE.
      From 412 projects, 232 (26) have differences larger than 0.10 (0.15) mas in YPOLE.
      From 412 projects, 104 (9) have differences larger than 10 (30) microseconds in UT1-UTC.

      

      EOP difference 2011

      by Amy Mioduszewski last modified Aug 18, 2011
      Difference in EOPs from correlation and the best USNO numbers from all the experiments in 2011 (through Aug 17, 2011).
        Obs     MJD    diff X   diff Y  diff UT1  combined
      [mas] [mas] [ms] [mas]
      ----------------------------------------------------
      bb240ew 55564 -0.05 0.11 -0.004 0.13
      bb240ex 55571 -0.10 0.06 0.006 0.15
      bb240ey 55581 -0.05 0.03 -0.017 0.26
      bb240ez 55591 -0.06 0.06 -0.009 0.16
      bb293b 55568 -0.03 0.00 -0.024 0.36
      bc195 55572 -0.08 0.09 0.024 0.38
      bc196a 55574 -0.13 0.04 -0.001 0.14
      bc196b 55577 -0.15 0.08 -0.015 0.28
      bc196c 55581 -0.14 0.07 -0.029 0.46
      bc196d 55583 -0.13 0.03 -0.008 0.18
      bd151 55573 -0.12 0.08 -0.007 0.18
      bd152a7 55591 -0.06 0.06 -0.009 0.16
      bd152ai 55568 -0.08 0.06 -0.022 0.34
      bd152aw 55570 -0.07 0.05 0.000 0.09
      bd152ax 55565 -0.11 0.10 0.007 0.18
      bd152b6 55576 -0.11 0.07 -0.006 0.16
      be057b 55579 -0.11 0.11 -0.028 0.45
      bf104a 55579 -0.11 0.11 -0.028 0.45
      bg201 55592 -0.07 0.06 0.002 0.10
      bg205a 55585 -0.06 0.02 -0.001 0.07
      bg207a 55575 -0.13 0.04 -0.011 0.21
      bm303o 55564 -0.05 0.11 -0.004 0.13
      bo038b 55582 -0.08 -0.02 -0.004 0.10
      bo038c 55578 -0.12 0.06 -0.025 0.40
      bp161b 55569 0.01 -0.03 0.002 0.04
      bp161c 55572 0.04 0.05 -0.001 0.07
      br145f5 55592 -0.07 0.05 0.003 0.10
      br145k2 55565 -0.11 0.10 0.007 0.18
      br152b 55593 -0.09 0.03 0.005 0.12
      br156 55586 -0.04 0.02 0.003 0.06
      br158 55582 -0.17 0.01 -0.025 0.41
      bs206c 55570 -0.07 0.05 0.000 0.09
      bs206d 55574 -0.13 0.04 -0.001 0.14
      bs206f 55581 -0.14 0.07 -0.029 0.46
      bs206g 55568 -0.08 0.06 -0.022 0.34
      bw094g 55566 -0.12 0.06 0.004 0.15
      bw094h 55580 -0.12 0.12 -0.034 0.54
      by128c 55570 -0.02 -0.00 -0.001 0.03
      bb240fa 55594 -0.05 0.00 0.000 0.05
      bb240fb 55600 -0.06 0.02 -0.014 0.22
      bb240fd 55616 -0.05 0.03 -0.005 0.10
      bb261v 55605 -0.08 -0.00 -0.007 0.13
      bb300a 55612 -0.08 0.00 -0.006 0.12
      bc170cd 55607 -0.09 -0.02 -0.018 0.29
      bc189a 55620 -0.09 0.03 -0.014 0.23
      bc196e 55593 -0.09 0.03 0.005 0.12
      bc196f 55599 -0.06 -0.01 0.005 0.10
      bc196g 55608 -0.11 0.00 -0.008 0.16
      bc196h 55611 -0.09 0.00 -0.006 0.13
      bc196i 55619 -0.09 0.03 -0.011 0.19
      bd152a6 55611 -0.09 0.00 -0.006 0.13
      bd152ag 55601 -0.08 0.05 -0.005 0.12
      bd152aj 55595 -0.11 0.04 0.001 0.12
      bd152aq 55597 -0.12 -0.02 0.006 0.15
      bg207b 55617 -0.12 -0.01 -0.001 0.12
      bj067c 55613 -0.08 0.01 -0.008 0.14
      bj073 55621 -0.10 0.00 -0.027 0.42
      bl149db 55613 -0.07 0.01 -0.006 0.11
      bl149dc 55620 -0.09 0.03 -0.014 0.23
      bm272if 55619 -0.07 0.02 -0.011 0.18
      bm303p 55597 -0.12 -0.02 0.006 0.15
      bm321d 55606 -0.07 0.00 -0.002 0.08
      br145i3 55608 -0.11 0.00 -0.008 0.16
      br145j1 55618 -0.05 0.01 -0.001 0.05
      br145r3 55604 -0.09 0.00 -0.011 0.19
      br145u3 55609 -0.10 0.02 0.000 0.10
      br145v2 55614 -0.06 0.04 -0.012 0.19
      bs206h 55600 -0.06 0.02 -0.014 0.22
      bw094i 55596 -0.13 0.03 0.026 0.41
      bw094j 55618 -0.05 0.01 -0.001 0.05
      bw095b 55605 -0.08 -0.00 -0.007 0.13
      by128f 55609 -0.10 0.02 0.000 0.10
      bb240fe 55625 -0.12 0.00 -0.008 0.17
      bb240ff 55630 -0.13 0.02 -0.001 0.13
      bb240fg 55643 -0.05 0.02 -0.028 0.42
      bb240fh 55647 -0.16 0.03 -0.024 0.40
      bb293c 55639 -0.10 0.02 -0.001 0.10
      bb300b 55635 -0.11 0.02 0.002 0.12
      bc196j 55632 -0.13 0.04 -0.001 0.14
      bc196k 55634 -0.11 0.03 0.005 0.14
      bc196l 55644 -0.13 0.03 -0.016 0.27
      bd152am 55633 -0.12 0.03 0.004 0.14
      bd152b7 55628 -0.12 0.00 0.004 0.13
      bd152b8 55636 -0.06 -0.01 0.000 0.06
      bf100g 55628 -0.12 0.00 0.004 0.13
      bg207c 55649 -0.15 0.02 -0.009 0.20
      bh165a 55627 -0.12 0.02 -0.005 0.14
      bh165c 55643 -0.05 0.02 -0.028 0.42
      bh165d 55650 -0.12 0.05 -0.008 0.18
      bl149dd 55626 -0.11 0.03 -0.008 0.17
      bl176e 55646 -0.14 0.05 -0.012 0.23
      bm303q 55622 -0.11 -0.02 -0.008 0.16
      bm336a 55646 -0.14 0.05 -0.012 0.23
      bm336b 55647 -0.16 0.03 -0.024 0.40
      bm336c 55649 -0.15 0.02 -0.009 0.20
      bm336d 55650 -0.13 0.05 -0.008 0.18
      br145ba 55634 -0.11 0.03 0.005 0.14
      br145ca 55626 -0.11 0.03 -0.008 0.17
      br145cb 55632 -0.13 0.04 0.000 0.14
      br145cc 55646 -0.14 0.05 -0.012 0.23
      br145g6 55642 -0.14 0.08 -0.049 0.75
      br145h6 55628 -0.12 0.00 0.004 0.13
      br145i4 55647 -0.16 0.03 -0.024 0.40
      br145k3 55629 -0.12 0.02 0.001 0.12
      br145m1 55640 -0.10 -0.01 0.015 0.25
      br145q1 55641 -0.13 0.02 -0.040 0.61
      br145r4 55639 -0.10 0.02 -0.028 0.43
      br145t1 55650 -0.13 0.05 -0.008 0.18
      br145u4 55649 -0.15 0.02 -0.009 0.20
      br152c 55642 -0.14 0.08 -0.049 0.75
      br161a 55651 -0.09 0.02 -0.004 0.11
      bw094k 55635 -0.11 0.02 0.002 0.12
      bw094l 55648 -0.15 0.05 -0.011 0.23
      gc034e 55636 -0.06 0.02 -0.002 0.07
      gc034f 55637 -0.04 0.00 -0.009 0.14
      bb240fi 55662 -0.00 0.00 0.005 0.07
      bb240fl 55682 -0.01 -0.07 0.002 0.08
      bb296 55673 -0.02 -0.01 -0.002 0.04
      bb298c 55674 -0.02 -0.03 0.002 0.05
      bb298d 55677 -0.02 -0.04 0.005 0.09
      bb298e 55655 -0.17 0.03 -0.002 0.18
      bb298f 55658 -0.14 0.02 -0.006 0.17
      bb300c 55672 -0.04 0.00 -0.009 0.14
      bb304a 55652 -0.04 0.03 -0.011 0.17
      bb304b 55654 -0.12 0.01 0.004 0.13
      bc196m 55670 -0.07 -0.01 -0.003 0.08
      bc196n 55677 -0.02 -0.04 0.005 0.09
      bd152b9 55678 -0.08 -0.03 -0.005 0.11
      bd154a 55668 -0.08 0.00 -0.003 0.09
      bf104b 55674 -0.02 -0.03 0.002 0.05
      bg207d 55676 -0.01 -0.03 0.012 0.18
      bl149df 55663 -0.11 0.00 0.004 0.13
      bl175a0 55654 -0.08 0.01 0.003 0.09
      bl182 55681 -0.05 -0.05 -0.008 0.14
      bm303r 55673 -0.02 -0.01 -0.001 0.03
      bm336e 55653 -0.09 0.02 -0.002 0.10
      bm336f 55655 -0.17 0.03 -0.002 0.18
      bm336g 55656 -0.16 0.05 -0.022 0.37
      bm336h 55660 -0.15 0.03 0.002 0.16
      br145bb 55657 -0.13 0.01 -0.017 0.29
      br145bc 55670 -0.11 0.00 -0.006 0.14
      br145d6 55677 -0.02 -0.04 0.005 0.09
      br145j2 55661 -0.07 0.00 0.003 0.08
      br145k4 55668 -0.08 0.00 -0.003 0.09
      br145l1 55667 -0.10 0.03 -0.003 0.11
      br145n1 55653 -0.09 0.02 -0.002 0.10
      br145o1 55655 -0.17 0.03 -0.002 0.18
      br145v3 55682 -0.01 -0.07 0.002 0.08
      bs210a 55653 -0.09 0.02 -0.002 0.10
      bs210b 55659 -0.17 0.05 0.001 0.18
      bw094m 55662 -0.13 -0.01 0.003 0.14
      bw094n 55674 -0.02 -0.03 0.002 0.05
      by128g 55680 -0.08 -0.01 -0.001 0.08
      bb240fm 55696 -0.04 -0.03 -0.001 0.05
      bb240fn 55702 0.00 0.01 0.000 0.01
      bb293d 55694 -0.05 -0.04 0.002 0.07
      bb297a 55697 -0.05 -0.02 -0.001 0.06
      bb297b 55698 -0.04 -0.07 -0.007 0.13
      bb298a 55683 -0.01 -0.04 -0.013 0.20
      bb298b 55684 -0.03 0.01 -0.045 0.68
      bb300d 55707 -0.03 -0.06 -0.003 0.08
      bc170ce 55683 -0.01 -0.04 -0.013 0.20
      bc196o 55695 -0.03 -0.05 0.002 0.07
      bc196p 55696 -0.04 -0.03 0.000 0.05
      bc196q 55698 -0.04 -0.07 -0.007 0.13
      bc196r 55712 -0.02 -0.05 -0.009 0.15
      bg207e 55713 -0.02 -0.06 -0.031 0.47
      bl149dh 55703 -0.02 -0.04 0.001 0.05
      bl149di 55708 -0.01 -0.02 -0.019 0.29
      bm303s 55704 -0.02 -0.04 -0.009 0.14
      br138c 55685 -0.06 -0.03 -0.008 0.14
      br145e6 55695 -0.03 -0.05 0.002 0.07
      br145f6 55713 -0.02 -0.06 -0.031 0.47
      br145i5 55702 -0.01 -0.04 -0.009 0.14
      br145p1 55697 -0.05 -0.02 -0.001 0.06
      br145r5 55693 -0.08 -0.02 0.000 0.08
      br145s1 55706 -0.03 -0.07 -0.005 0.11
      br145u5 55706 -0.03 -0.07 -0.005 0.11
      br145v4 55711 -0.04 -0.03 -0.003 0.07
      br152d 55696 -0.04 -0.03 -0.001 0.05
      bs210c 55686 -0.06 -0.04 -0.001 0.07
      bs210d 55709 -0.02 -0.06 -0.005 0.10
      bw094o 55685 -0.06 -0.03 -0.008 0.14
      bw094p 55701 -0.01 -0.03 -0.021 0.32
      bb240fp 55729 -0.05 -0.01 -0.006 0.10
      bb240fq 55731 -0.02 -0.06 0.001 0.07
      bb286e 55738 -0.02 -0.03 0.000 0.04
      bb297c 55724 -0.03 0.00 0.000 0.03
      bc196s 55716 -0.05 -0.01 -0.011 0.17
      bc196t 55720 -0.02 -0.02 0.003 0.05
      bc196u 55726 -0.01 -0.01 -0.002 0.03
      bc196v 55732 -0.03 -0.07 -0.001 0.08
      bc196w 55734 -0.03 -0.03 0.021 0.32
      bd156 55715 -0.04 -0.08 -0.016 0.26
      bg207f 55742 -0.01 -0.04 -0.013 0.20
      bl149dj 55719 -0.02 -0.06 0.011 0.18
      bl149dk 55731 -0.02 -0.06 0.001 0.07
      bl149dl 55737 0.00 -0.00 0.002 0.03
      bm303t 55725 -0.05 0.00 0.000 0.05
      br145j3 55742 -0.01 -0.04 -0.013 0.20
      br145k5 55715 -0.04 -0.08 -0.016 0.26
      br145m2 55732 -0.03 -0.07 -0.001 0.08
      br145n2 55739 -0.01 -0.03 0.002 0.04
      br145o2 55740 -0.01 0.01 0.001 0.02
      br145t2 55738 -0.02 -0.03 0.000 0.04
      br161b 55718 0.01 -0.04 0.000 0.04
      bw094q 55715 -0.04 -0.08 -0.016 0.26
      bw094r 55729 -0.05 -0.01 -0.006 0.10
      bw096a1 55723 -0.01 -0.04 0.003 0.06
      bb240fs 55744 -0.02 -0.03 -0.004 0.07
      bb240ft 55746 -0.04 -0.06 0.003 0.08
      bb240fu 55753 0.00 -0.00 0.001 0.01
      bb240fv 55765 -0.01 -0.03 -0.003 0.05
      bb307 55748 -0.08 -0.02 0.014 0.23
      bb307b 55771 0.04 -0.05 0.000 0.06
      bc196x 55767 0.00 -0.08 0.000 0.08
      bc196y 55769 -0.06 -0.04 0.002 0.08
      bd152al 55762 -0.05 -0.04 0.003 0.08
      bd152an 55768 -0.01 -0.03 0.005 0.08
      bd152as 55743 -0.04 -0.01 -0.009 0.14
      bd152b0 55752 -0.05 -0.06 0.001 0.08
      bd152b1 55749 -0.04 -0.06 0.008 0.14
      bd152b2 55761 -0.03 -0.02 0.037 0.56
      bd152b3 55750 -0.04 -0.05 0.005 0.10
      bd152b5 55756 -0.06 -0.03 0.005 0.10
      bf104c 55766 -0.03 -0.05 0.001 0.06
      bg207g 55771 0.03 -0.05 -0.002 0.07
      bg208a 55769 -0.06 -0.04 0.002 0.08
      bl149dm 55758 -0.07 -0.05 0.000 0.09
      bl175a1 55747 -0.02 -0.04 0.008 0.13
      bl179a 55745 -0.03 -0.04 0.000 0.05
      bl179b 55754 -0.08 -0.04 -0.003 0.10
      br145l2 55744 -0.02 -0.03 -0.003 0.06
      br145v5 55759 -0.02 -0.05 -0.002 0.06
      br152e 55750 -0.04 -0.05 0.005 0.10
      bs212a 55760 -0.01 0.00 0.004 0.06
      bt117a 55759 -0.02 -0.05 -0.002 0.06
      bt117b 55774 0.00 0.00 0.000 0.00
      bw094s 55744 -0.02 -0.03 -0.003 0.06
      bw094t 55758 -0.07 -0.05 0.000 0.09
      bw094u 55772 -0.00 -0.05 0.001 0.05
      by128e 55750 -0.04 -0.05 0.005 0.10
      ----------------------------------------------------
      Maximum difference between used and final EOPs:
      XPOLE: 0.17 mas; YPOLE: 0.12 mas; UT1-UTC: 0.049 milliseconds; combined: 0.75 mas.

      From 242 projects, 72 (14) have differences larger than 0.10 (0.15) mas in XPOLE.
      From 242 projects, 7 (0) have differences larger than 0.10 (0.15) mas in YPOLE.
      From 242 projects, 61 (8) have differences larger than 10 (30) microseconds in UT1-UTC.

      

      Accurate Source Position Service

      by Amy Mioduszewski last modified Nov 28, 2016 by Jonathan Romney

      NRAO offers to provide astrometric quality source positions in response to requests from users.  The positions are measured during the joint NASA/USNO/NRAO 20 station geodetic/astrometric observations that occur about every 2 months and that mainly serve other purposes.  A few sources can be measured during each of these observations.  Formal position errors of between 0.1 and 3 mas have been obtained for sources measured under this program in the past.

      Requests for positions should be received well ahead of the time when they are needed, for example, for use on a VLBI correlator.  It takes a minimum of 2 to 4 months to obtain a position because of the wait between observing runs and the amount of time it takes to schedule, observe, fringe search, correlate, release, and reduce these large runs.  If a position must be available for processing of another observation, the request should be made no later than when the other observations are proposed.  Also, don't request too many sources.  Only a small number can be added to each run.

      If you have a source for which you need a position, first check that it really qualifies.  We have received a number of requests for sources that were too weak, or for which good positions were already available.  A source should have at least 0.1 Jy at 2.3 and 8.4 GHz and there should be some indication, either from past observations or from a flat spectrum, that it can be seen with VLBI.  A good place to check for known source positions is at the USNO Web site. Also, VLA positions for a large number of sources from the JVAS survey, good to 12-55 mas, are available by anonymous ftp at ftp.aoc.nrao.edu in file pub/sources.jvas.

      Requests for positions may be made by email to jromney@lbo.us.  Please include the following information:

      1.  A short scientific justification.
      2.  Source names.
      3.  Source coordinates good to at least 0.5 arcseconds.
      4.  The expected flux densities at 2.3 and 8.4 GHz.
      5.  Evidence that there will be compact structure.

      Requests for positions of more than 10 sources will not be considered. Accepted sources will be observed as soon as possible and positions will be returned by email.  The results will be public domain immediately and source positions, and in many cases, even images will appear on the geodetic web sites.

      If source positions obtained through this service are used in a publication, or are instrumental in obtaining the results in a publication, please include an acknowledgement that the source positions were provided by observations from the joint NASA/USNO/NRAO geodetic/astrometric observing program and that the positions are in the frame of the ICRF2 catalog.T he ICRF2 catalog is the official IAU reference frame.  A detailed description of the ICRF2 can be found in the IERS Technical Note 35 (2009).  An acknowledgement will be appreciated by the NASA and USNO groups that actually do most of the work to derive the positions.

      Technical Justification page 1

      by Amy Mioduszewski last modified May 15, 2015
      VLBA Technical Justification Page 1
      Technical Justification page 1
      Full-size image: 170 KB | View image View Download image Download

      Technival Justification Page 2

      by Amy Mioduszewski last modified May 15, 2015
      VLBA Technical Justification Page 2
      Technival Justification Page 2
      Full-size image: 135 KB | View image View Download image Download

      VLBA Technical Justification Example

      by Amy Mioduszewski last modified Jul 29, 2015

      Technical Justification for Proposals

      Since the actual Technical Justification depends strongly on the science, the frequencies and correlator setup, etc. it is difficult to give general guidelines.  Instead, we present the example below, in this for case multi-epoch astrometry.  Click to enlarge.

      Technical Justification page 1
      VLBA Technical Justification Page 1
      Technival Justification Page 2
      VLBA Technical Justification Page 2

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 31 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 37 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 21 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 31 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 36 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 28 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 36 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 40 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 43 KB | View image View Download image Download

      by Claire Chandler last modified Mar 13, 2016

      Full-size image: 41 KB | View image View Download image Download

      by Claire Chandler last modified Mar 16, 2016

      Full-size image: 29 KB | View image View Download image Download

      by Claire Chandler last modified Mar 16, 2016

      Full-size image: 37 KB | View image View Download image Download

      by Claire Chandler last modified Mar 16, 2016

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      by Claire Chandler last modified Mar 16, 2016

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