Subject: [IGSLEO-45] JASON campaign
From: [email-masked]
To: [email-masked]
Date: Thu, 16 Jan 2003 18:37:07 +0100

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IGS LEO Mail      16 Jan 09:37:20 PST 2003      Message Number 45
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Author: Henno Boomkamp

Dear colleagues,

A reasonable number of IGS LEO centres now seems to
be working on JASON-1 data, so that I would like to formally
launch the long-overdue JASON orbit campaign.

The campaign period has been selected to cover the three
JASON cycles 15, 16 and 17 (June 2001). This period was
selected for being relatively free of satellite events.

Interested centres are invited to contribute the following:
   (a) A short 'readme' file that characterizes your orbit solution.
         What is in particular important is to clearly identify the tracking
data
         that was used, including relevant reference systems. For example:
             * GPS undifferenced pseudorange and phase, using fixed IGS
                final orbits and clocks as reference,
             * DORIS data, using ITRF2000,
             * Altimetry crossovers, maximum time separation of three days,
              * ..... etc.
        Any further modelling information may be added that you consider
        relevant, e.g., attitude quaternions used or not, which parameters
        were estimated, which gravity field model was used.

   (b) SP3 orbit files for JASON-1 that cover the full campaign period.
         The recommended format is:
          * Arc length either: 26-hr arcs, all starting at 00:00 (2 hr arc
overlaps)
             or:  full JASON cycles, with 2 hrs extra at both arc boundaries.
          * Step size: 60 seconds
          * Velocity data included (... if absent, it will be added by
interpolation)
          * JASON-1 satellite ID number for SP3 is L08
         Other formats can in most cases be accepted as well, but may lead to
         loss of precision due to required interpolations, time conversions,
etc.

   (c) If GPS data is used for the solution, please provide the JASON receiver
         clock solutions also. This can be done using the clock field in the SP3
         data records, but un-interpolated clocks in any reasonable file format
         are preferred over interpolated clocks in SP3 files.

Contributions can be uploaded to your own CDDIS account, if you have one, or
to the public CDDIS account ~pub/incoming. Please send an e-mail notification
afterwards either to [email-masked] or to [email-masked]
so that your orbits will be processed. The analysis results for JASON will
appear
as soon as possible at http://nng.esoc.esa.de/gps/igsleo.html.

Note 1: The ~gps/products/leopp  directory at cddis will from now on have
                subdirectories per LEO mission. The current ~/leopp/ directory
will
                become the new ~leopp/champ/ directory.

Note 2: Multiple contributions per centre are welcome, as are later updates.
               For JASON all contributed orbits will be kept on-line to avoid
confusion
               about solution versions that are used in any particular analysis.

Please feel free to contact me for any further questions or comments.
Thank you in advance for your efforts, and best regards,

Henno Boomkamp