[IGSMAIL-94] IGS Status Report, September 14, 1992

[Gerhard]

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IGS Electronic Mail       14-SEP-1992 10:52:50       Message Number 94
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>From:    Gerhard Beutler
Subject: IGS Status Report, September 14, 1992
         _____________________________________


IGS Status Report, September 14, 1992
_____________________________________

General Remarks :

 - The 1992 IGS Campaign started almost 12 weeks ago, there are
   only three more weeks until the official end of the campaign:
   This means that we have to think about the future (see below).

 - Regular analyses are produced by CSR, Austin, ESOC, Darmstadt GFZ
   Potsdam, and JPL, Pasadena, SIO , San Diego, and CODE, Berne.
   First attempts to use the products from individual processing
   centers indicate that they all are of excellent quality, clearly
   superior to the broadcast ephemerides in any case !

 - Two earth rotation bulletins were issued so far, Dennis McCarthy is
   comparing the earth rotation parameters regularly with the IERS
   rapid service results. The results are encouraging, reports may be
   found at weekly intervals in the IGS mailbox.

 - IGS earth rotation parameters are now used for prediction by
   the IERS rapid service.

 - Anti-spoofing was activated during weekends, starting on August 1
   (Unfortunately in the middle of the Epoch'92 campaign). AS prooves
   to be a serious problem for IGS at present. The only solution (at
   present) seems to be to ignore the observations from these satellites
   for the time period AS was turned on. This situation is not satis-
   factory : we will have to come up with a solution (a) for the two
   weekends within the Epoch campaign (August 1, August 7), and (b)
   for the future.


(1) The IGS Campaign 1992 and its Continuation
    __________________________________________

 - In view of the results from the 1992 IGS campaign 1992 listed above
   there can be no doubt that this campaign actually is a success :
   Data collection, transmission, and transformation has not caused
   any serious problems, a surprisingly large number of processing
   centers are producing high quality products within a reasonable
   timeframe.  In summary :  we were able to generate a remarkable
   momentum during this summer.

 - Some of the institutions participating in the 1992 IGS campaign will
   continue their work after September 1992 : This is true in particular
   for the agencies collecting and archiving data. I was especially glad
   to learn that CDDIS, JPL, SIO, and IGN are ready to continue with their
   work.

 - Therefore, a few weeks ago, in consultation with Prof. Ivan I.
   Mueller representing I.A.G.,I started inquiring the possibility of
   NOT ending the campaign on September 23, but to continue with a
   kind of a "preliminary" service after 23 of September.  I wrote a
   letter to Prof.  Torge, president of IAG, requesting approval from
   the IAG Bureau to continue the 1992 IGS campaign.  The answer was
   positive.

 - The next step was (a) to inform the members of the oversight committee
   of these activities and (b) to officially ask all data centers and
   processing centers whether or not they were supporting the idea of
   a continuation of the campaign.

 - The answers may be summarized as follows :

    - Everybody agreed that the momentum generated should not be lost.

    - There were some suggestions to bring in additional participants
      especially for the fiducial stations. This would require
      additional time.

    - All data centers (needed for the Core network) and the majority
      of processing centers are willing to continue with their work.

    - There were strong objections to just turning the 1992 IGS campaign
      into some kind of a preliminary service. It was felt that such a
      procedure is problematic from a formal point of view, it was
      furthermore argued that those institutions not able to continue
      due to budgetary or other restrictions might automatically and
      unfairly be left out for the final service.

 - Therefore Ivan Mueller and I suggest to proceed as follows :

    - We officially close the 1992 IGS campaign as scheduled on
      September 23, 1992. The performance of the processing centers
      within the timeframe 21 June - 23 September will be the basis
      for evaluation of the future IGS service.

    - Data collection, archiving, AND data processing will continue after
      September 23. I URGE ALL DATA- and PROCESSING CENTERS TO CONTINUE
      with their work UNTIL THE END OF OCTOBER 1992 fo the purpose of
      maintaining the momentum developed during the three-month
      campaign until the Oversight Committee has an opportunity to
      meet and discuss formal plans.  This, in principle, is
      equivalent to the EXTENSION of the 1992 IGS CAMPAIGN for about
      five weeks, which will allow the IGS oversight committee to
      discuss the future at its next official meeting:

    - At the Goddard meeting (15/16 October 1992) of the IGS oversight
      committee we will decide on the official status of the IGS  
      activities between November 1992 and the submission of the IGS
      proposal to IAG resp. the subsequent possible start of the
      service.

 - I will inform the IAG Bureau of this new procedure.


(2) Campaign Oversight Committee Meeting, 15/16 October 1992
    ________________________________________________________

 - As announced earlier the next IGS campaign oversight committee
   meeting will take place at the Goddard space flight center (after
   the DOSE Working Group Meeting).

 - The meeting will have the form of a workshop.  We hope to see the
   members of the oversight committee and many participants of the 1992
   IGS experiments at the workshop.  We will start on Thursday, 15 October
   (at 2 pm), and continue on Friday for the entire day. The agenda will
   follow.

 - Those of you having received the first announcement of the DOSE
   meeting have seen that IGS is scheduled as one of the topics of the
   DOSE meeting. Greenbelt seems to be worth a trip in October -- if
   you are interested in IGS.



(3) IAG-Symposium 112 in Potsdam , 5 - 10  October 1992
    ___________________________________________________

 - There will be a session on IGS at the Potsdam Symposium on "Geodesy
   and Physics of the Earth".

 - There will be NO official oversight committee meeting at the
   Potsdam symposium. An informal discussion will be scheduled
   however to discuss/finalize the agenda for the Goddard meeting of
   the following week with those oversight committee members present
   in Potsdam.

(4) Post Campaign Meeting in Spring 1992
    ____________________________________

 - The Post Campaign Workshop (covering the 1992 IGS campaign AND
   Epoch'92) in spring 1992 will be organized at the University of
   Berne in the week of 22 - 26 March, 1993 (this is the week
   preceeding the Amsterdam IAG workshop on differential GPS in
   Amsterdam).

 - At this workshop we should prepare a first draft of the IGS
   proposal to IAG in order to be able present it at the IAG General
   Meeting in Beijing.


                                                    Kind regards

                                                   Gerhard Beutler
                                                   Ivan I. Mueller