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IERS Message No. 27: IERS SINEX Combination Campaign
by central_bureau＠iers.org May 28, 2002

May 28, 2002

*************************************************************************** IERS Message No. 27 May 28, 2002 *************************************************************************** IERS SINEX Combination Campaign Call for Participation Objective: It is the intention of this campaign to combine 'weekly' solutions from SINEX files of different techniques with station coordinates and EOPs (and ICRF) and to assess systematic biases between the individual techniques. New combination strategies should be developed by the combination centres and the comparison of the different combined solutions should result in an improvement of strategies, modeling and parameterization. If appropriate combination methods are found, the combined 'weekly' solutions may serve in the future as the basis for routine EOP products and, as a long term goal, we can combine the 'weekly' solutions into 'multi-year' solutions including ITRF + EOP + ICRF, where the resulting ITRF and ICRF are used to produce fully consistent EOP series. The IERS SINEX Combination Campaign will be organized in two major steps: 1. Generation of solutions in SINEX (preferably 'weekly' solutions) for the year 1999 (or more) with station coordinates + EOP (+ ICRF) by the Analysis Centres of the individual techniques (Technique Centres) or other interested groups. 2. Testing and combination of the 'weekly' technique solutions by the IERS Combination Research Centres and other interested groups. Creation of a SINEX data pool (preparation step; done by the IERS Analysis Coordinator): A data pool with SINEX files of the year 1999 of different techniques is already established. It contains - 28-days SLR solutions of eleven ILRS Analysis Centres that originate from the ILRS pilot project 'positioning and earth orientation' - VLBI solutions of all 1999 sessions generated by GSFC and IAA - links to the weekly solutions of the seven IGS Analysis Centres of the appropriate weeks of the year 1999 - weekly DORIS solutions for the year 1999, produced as a joint effort of IGN and JPL - ITRF2000 for each technique - local ties (unfortunately not yet in SINEX format) This data pool is accessible to everybody via the web site of the IERS Analysis Coordinator http://alpha.fesg.tu-muenchen.de/iers/sinex/datapool.html and it will be extended with the solutions contributing to the IERS SINEX Combination Campaign. Generation of SINEX solutions (first step): In the first step of this campaign, the Technique Centres or other interested groups are asked to produce 'weekly' solutions for the year 1999 and deliver them in SINEX format to the IERS: - use ITRF2000 as terrestrial reference frame - do not use tight constraints (use either loose constraints or minimum constraints) - if you use constraints, please submit (free) SINEX solutions as well for testing purposes, to check whether the constraints are completely removable. Please respect the official format definition of SINEX, accessible via the web site of the IERS Analysis Coordinator as well: http://alpha.fesg.tu-muenchen.de/iers/ The submitted solutions will be archived in the SINEX data pool described above and made available to all participating groups for the second step. Combination of SINEX files (second step): The IERS Combination Research Centres and other interested groups test and combine these technique-specific SINEX solutions: - detection of systematic biases between techniques - test of different combination strategies - improvement of strategies, modeling and parameterization The first results may be presented at the IERS Combination Research Workshop in Munich in early November 2002. The presentation of final results and recommendations on strategies, modeling, standards, ... is planned for the EGS General Assembly in Nice 2003. If you are interested in producing and / or combining such SINEX files or contribute to this campaign in any another way, please fill out the attached call for participation form! You can either submit the form via email or you can send us a hardcopy (fax or mail). Please submit your proposal by June 15, 2002! Munich, 27.05.2002 Markus Rothacher, Daniela Thaller IERS Analysis Coordination --------------------------------------------------------------------------- + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + --------------------------------------------------------------------------- IERS SINEX Combination Campaign Call for Participation Form Recipient: IERS Central Bureau Bundesamt fuer Kartographie und Geodaesie Richard-Strauss-Allee 11 60598 Frankfurt am Main Germany fax: ++49-69-6333-425 email: central_bureau(a)iers.org or Markus Rothacher IERS Analysis Coordinator Forschungseinrichtung Satellitengeodaesie Technische Universitaet Muenchen Arcisstr. 21 80333 Muenchen Germany fax: ++49-89-289-23178 email: Markus.Rothacher(a)bv.tum.de Who is participating? Name (primary scientist): Organization or institute: Mailing address: Phone: Fax: Email: Cooperating organizations / institutes: Research associates: Generation of SINEX solutions (first step): Will you generate SINEX solutions? yes/no What type of SINEX solutions will you produce? Technique (VLBI, GPS, SLR, ...): Time span of all submitted solutions (the whole year 1999 or otherwise): Period covered by each single solution (weekly, monthly, ...): Reference frame used: Constraints used: Reference sites used: Description of solution: Analysis approach used: Comments on your solutions: Suggestions: Combination of SINEX files (second step): Are you interested in combining SINEX solutions? yes/no Proposed analysis (short description): Suggestions: Schedule Deadline for proposals: June 15, 2002 Envisaged deadline for submission of SINEX files (preferably before August 15, 2002): For a more detailed description of your project you can attach your own proposal as file. Attachement: *************************************************************************** IERS Messages are edited and distributed by the IERS Central Bureau. To subscribe or unsubscribe, please write to <central_bureau(a)iers.org>. Archives: http://www.iers.org/iers/publications/messages/ ***************************************************************************

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UTC Questionnaire
by iers＠hpopa.obspm.fr May 27, 2002

May 27, 2002

Subject: Questionnaire regarding the use of UTC Dear colleague We are addressing the attached questionnaire to users of Bulletin C and/or D in order to survey opinion concerning a possible redefinition of UTC. UTC (Coordinated Universal Time) is computed from TAI by the introduction of leap seconds such that UTC is maintained within 1 second of UT1. Since 1972, these leap seconds have been added on December 31 or June 30, at the rate of about one every 18 months. The relevant bulletins are: > Bulletin C: Announcement of the leap seconds in UTC. > Bulletin D: Announcement of the value of DUT1 truncated at 0.1s for transmission with time signals. Recently, some communities linked to telecommunications and navigational systems have proposed a revision of the definition of UTC to avoid the discontinuities due to the intermittent leap seconds. The object of our survey is to find out the strength of opinion for maintaining or changing the present system within Bulletins C and D users. We would also like to know your interests and needs, current and future. I apologize if you receive this questionnaire twice. Thank you for devoting some of your time to this important topic. Daniel Gambis Head Earth Orientation Center of IERS ============================================================================= Please return this form by 30 June 2002 to the IERS Earth Orientation Center: iers(a)obspm.fr Thanks for your time and attention. Mark your answer with a X [X] and add any comments. 1 - Your identification Name : Institute: Adress : e-mail : 2 - Field of activity Time [ ] Telecommunication [ ] Astronomy/Astrophysics [ ] Geophysics [ ] Space sciences [ ] Geodesy [ ] Navigation [ ] Other? What? [ ] 3 - Are you satisfied by the current UTC determination method with leap second adjustements? YES [ ] NO [ ] 3-1 if YES Is the present forecast time (6 months in advance) of the occurence of a leap second sufficient. If not would you suggest another time delay? 1 year or more? 3-2 if NO Why ? 4 - Do you think it would be better to change the determination method of UTC? YES [ ] NO [ ] NO OPINION [ ] 4 -1 If YES, which alternative solution would you favour? a. No leap second [ ] a.1 UTC without further leap seconds [ ] a.2 Use TAI [ ] b. Increase tolerance for |UT1-UTC| [ ] c. Smooth over leap second step [ ] d. Redefine the second [ ] e. Some other possibility ? [ ] 4-2 If NO for 4, why? 5 - Other comments regarding the determination or operation of UTC? 6 - This question concerns Bulletin D users (DUT1 with 0.1s accuracy). Is the present Bulletin D appropriate ? YES [ ] NO [ ] If NO, why? If NO, would you prefer a more frequent and refined estimation? With what accuracy? END OF THE QUESTIONNAIRE

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IERS Message No. 26: SINEX Version 2.00
by central_bureau＠iers.org May 27, 2002

May 27, 2002

*************************************************************************** IERS Message No. 26 May 27, 2002 *************************************************************************** SINEX Version 2.00 Dear colleagues, After an intensive discussion about our proposed new format definition of SINEX, the final version SINEX 2.00 is available now. The detailed format description, a summary of the changes from version 1.00 to 2.00 and a summary of the important least squares adjustment formulas with their connection to the individual SINEX blocks are accessible via the web site of the IERS Analysis Coordination http://alpha.fesg.tu-muenchen.de/iers/ or via our ftp server ftp://alpha.fesg.tu-muenchen.de/iers/sinex/format/sinex_v2.txt A new format definition became necessary because different implementations of SINEX (originally for IGS purposes) existed from the ILRS and the IVS, and for the combination activities starting soon within the IERS (by the Combination Research Centres) a unique format definition for all space geodetic techniques is needed. All implementations were merged with the SINEX version 1.00 and were discussed intensively. We want to thank all people who were contributing to this discussion, especially the IGS Reference Frame Working Group chaired by Remi Ferland, the ILRS Analysis Coordinator Ron Noomen and the ILRS Analysis Working Group, the IVS Analysis Coordinator Axel Nothnagel and Zuheir Altamimi from the ITRF section of IGN. With their contributions and advice we created a SINEX format definition that is hopefully accepted by all Analysis Centres of each space geodetic technique. With best regards, Daniela Thaller, Markus Rothacher (IERS Analysis Coordination) *************************************************************************** IERS Messages are edited and distributed by the IERS Central Bureau. To subscribe or unsubscribe, please write to <central_bureau(a)iers.org>. Archives: http://www.iers.org/iers/publications/messages/ ***************************************************************************

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Correction to IERS Message No. 25
by central_bureau＠iers.org May 23, 2002

May 23, 2002

Please note that the correct address of the web site given in "1. General Introduction" is http://alpha.fesg.tu-muenchen.de/iers/ We apologize for any inconvenience this may have caused.

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IERS Message No. 25: Summary of the IERS Combination Research Mee ting
by central_bureau＠iers.org May 22, 2002

May 22, 2002

*************************************************************************** IERS Message No. 25 May 22, 2002 *************************************************************************** Summary of the IERS Combination Research Meeting, April 25, 2002 Dear colleagues, Please find hereafter a short summary of the IERS Combination Research Meeting, held on April 25, 2002 during the EGS General Assembly in Nice, France. With best regards, Daniela Thaller ----------------------------------------- Daniela Thaller Forschungseinrichtung Satellitengeodaesie Technische Universitaet Muenchen Arcisstrasse 21 D-80290 Muenchen / Germany Phone : ++49-89-289-23186 Fax : ++49-89-289-23178 E-mail: daniela.thaller(a)bv.tum.de ----------------------------------------- IERS Combination Research Meeting April 25, 2002 EGS XXVII General Assembly 2002 Acropolis Conference Centre, Nice, France 1. General Introduction - short overview over the agenda for the meeting given by M. Rothacher - web sites: http://www.alpha.fesg.tu-muenchen.de - two different mailing lists for CRC purposes: crc_forum(a)iers.org (open for all people interested in CRC activities; most part of the mails) crc(a)iers.org (only for internal purposes) 2. IERS Products present status and future perspective of the IERS products given by M. Rothacher: - preliminary overview of present IERS products is finished, but feedback and supplementation from some of the IERS product centres is still missing. - completed overview will soon be accessible via the IERS web pages. 3. IERS ERP Alignment Campaign The IERS Analysis Campaign to align EOPs to ITRF2000 / ICRF is already started. M. Rothacher gave a short overview: - aim: more consistent products - two steps: 1. Generation of EOP series (deadline for the submission was March 15, 2002) 2. Analysis of EOP series (final results should be presented at the IERS Workshop in November 2002) - status of the campaign: 10 VLBI series, 16 GPS series, 6 SLR series and 1 DORIS series First results of an analysis of the contributing EOP series, done by R. Dill (FESG / Technical University Munich), presented by M. Rothacher. Comments: - long term goal: use SINEX format for exchange of solutions (incl. variance-covariance information). - many ERP format problems / inconsistencies; common ERP format should be used. - IVS pilot project EOP series (1999-2000) not yet included (comment: now, these series are included as well). - this analysis should not be mixed with routine processing for the official IERS products; ERP Alignment Campaign is only for research purposes. - until now no other groups have analyzed the available EOP series (reason: contributing data available only since March 2002), but more analysis is necessary. - results from the different analysis groups are expected at the IERS Workshop in November 2002. 4. SINEX Combination Campaign A second campaign for the implementation of new combination strategies will be started. - combination of "weekly" solutions of different techniques with station coordinates + EOP + (ICRF) - development of standards for common modeling and parameterization - combined "weekly" solutions as the basis for final routine EOP products - combined multi-year solution (ITRF + ICRF) as basis to produce fully consistent EOP series The actual status and future plan was given by M. Rothacher: - SINEX datapool is already created (accessible via web sites of IERS Analysis Coordinator) with - weekly GPS solutions from IGS Analysis Centres - 28-days solutions of the ILRS pilot project 'positioning and earth orientation' 1999 - VLBI solutions from IAA for 1999 - time-table for contributions and combinations: - May 15, 2002: call for participation - June 15, 2002: deadline for submission of proposals - August 15, 2002: deadline for submission of series - November 2002, IERS Workshop: first results - April 2003, EGS: results Comments: - as input: not only one (already combined) solution per technique, but more individual solutions (because of research purposes). - older VLBI SINEX files are now available again from T. Herring; these will be included as input files as well (comment: the files of the year 1999 are now included). 5. SINEX format The proposed new format description is available on the web sites of the IERS Analysis Coordinator. M. Rothacher gave a short overview over the changes concerning SINEX 2.0 and presented the statements from IGS, IVS and ILRS. The final version of SINEX 2.0 will be available on May 15, 2002. Comments: - more explanatory text for the description of the blocks, parameters, formulas is required. - STATISTICS block 'strongly recommended' if information is available. - constraints problematical: tight constraints should be forbidden. - normal equations: tests will be performed if the constraints for every solution can be taken away and if the 'free' solution can be recovered. Normal equation blocks will be included in the format. - naming of a station after an earthquake not clear: use a new solution number, but do not change the DOMES number; difference to 'point ID': 4-character abbreviation + point ID corresponds exactly to a unique DOMES number - problems of distinguishing between GPS, GLONASS, (Galileo): at the moment the same code is used for these techniques, i.e. 'P' - parameters for solar radiation pressure will be kept. 6. CRC activities Short presentations from: - J. Vondrak: Astronomical Institute, Academy of Sciences of the Czech Republic - D. Angermann: DGFI - M. Rothacher: FESG, Technical University Munich - R. Gross: JPL Presentations during session G9.05 on Friday, April 26: - J. Vondrak: Astronomical Institute, Academy of Sciences of the Czech Republic - D. Angermann: DGFI - P.-H. Andersen: FFI - P. Yaya: GRGS - P. Sillard: IGN No presentations: - GFZ Potsdam - GIUB - IAA 7. Combination strategies No discussion at this meeting. 8. IERS Combination Workshop 4 days in early November 2002 in Munich - participants: all IERS components and contributing services. - topics: EOP; ITRS/ITRF; ICRS/ICRF; Contributions from Global Geophysical Fluids Centres (GGFC); Conventions/Standards; Rigorous combination of ITRF + EOP + ICRF; IAU Resolutions. - preparation with position papers for each session (available before the workshop). - coordination with IERS Directing Board to retain official character. 9. Varia No further topics and comments. *************************************************************************** IERS Messages are edited and distributed by the IERS Central Bureau. To subscribe or unsubscribe, please write to <central_bureau(a)iers.org>. Archives: http://www.iers.org/iers/publications/messages/ ***************************************************************************

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impending elsie.nci.nih.gov change
by Olson, Arthur David (NCI) May 7, 2002

May 7, 2002

We've milked elsie.nci.nih.gov, our SPARCstation 2 4/75, completely dry and are putting her out to pasture. In the next few days a new machine at a new IP address should be mooing at the same old elsie.nci.nih.gov name. In theory the changeover will be invisible, but if you see any glitches the problem may be at our end. --ado

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suggestion
by Arjun Manglani May 2, 2002

May 2, 2002

http://sandbox.xerox.com/stewart/tzconvert.cgi 1. For Asia/India, please add New Delhi and/or Bombay/Mumbai instead of Calcutta. Very few people would look up under the city name Calcutta. Bomaby and New Delhi are more famous - and these names come first when looking up for time in India. 2. Then there is a confusion of the DST - It would be better if just omit the note about the DST - just show the times as the person requests it - your program should take of the DST and the times - since the dates are plugged i the DST time is known from the date. Thanks. Arjun Manglani (718) 434-2134 Brooklyn, NY 11230 USA

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Tomsk, Russia now GMT+6, not GMT+7.
by Vadim Ostranitsyn May 1, 2002

May 1, 2002

Hi! Since 3:00am 1 May 2002 city Tomsk and Tomskaya oblast' has changed his timezone. Now Tomsk has GMT+6 timezone (as in Novosibirsk) instead of GMT+7. Act No.246 of Government of Russia (2002-04-17). p.s. Sorry for my awful english. -- Vadim Ostranitsyn Evil's flowers, VO45-RIPE, VO15-RIPN Tomsk State University, Russia

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RE: still more problems with the formatting in the tz datafiles
by Olson, Arthur David (NCI) April 29, 2002

April 29, 2002

The zic manual page notes that Input lines are made up of fields. Fields are separated from one another by any number of white space characters. so there's nothing "wild" about the format of the files. --ado -----Original Message----- From: Tony Blackmon [mailto:tblackmon@wilbursmith.com] Sent: Friday, April 26, 2002 2:54 PM To: tz(a)elsie.nci.nih.gov Subject: still more problems with the formatting in the tz datafiles i am finding more and more of these. each header comment is clearly marked with tabs delimiting the file, but when you get into the guts of the data some of these tabs are spaces. how do you parse the tzdata text files if the formatting is not correct? as i stated before, i am working under a windows environment, but still want to handle timezone conversion and client timezone selection using the tzcode data. it perplexes me as to how this all works with the data files formatted so wildly. is it meant to be this way or is all of this accidental or unnoticed? --fluid

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FW: still more problems with the formatting in the tz datafiles
by Olson, Arthur David (NCI) April 29, 2002

April 29, 2002

Tony Blackmon is not on the time zone mailing list; direct replies appropriately. --ado -----Original Message----- From: Tony Blackmon [mailto:tblackmon@wilbursmith.com] Sent: Friday, April 26, 2002 2:54 PM To: tz(a)elsie.nci.nih.gov Subject: still more problems with the formatting in the tz datafiles i am finding more and more of these. each header comment is clearly marked with tabs delimiting the file, but when you get into the guts of the data some of these tabs are spaces. how do you parse the tzdata text files if the formatting is not correct? as i stated before, i am working under a windows environment, but still want to handle timezone conversion and client timezone selection using the tzcode data. it perplexes me as to how this all works with the data files formatted so wildly. is it meant to be this way or is all of this accidental or unnoticed? --fluid

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