Subject: [ids.analysis.forum] DORIS station network for IDS combination
From: "Jean-Jacques Valette" <[email-masked]>
To: <[email-masked]>
Date: Mon, 19 Jan 2009 19:10:03 +0100

Dear colleagues

A combination of the IDS weekly solutions for station coordinates and EOPs is in preparation as a contribution to the ITRF2008 call for participation. 

Presently 7 ACs intent to participate delivering their best solutions (20th Jan. deadline) after a several months period of model and strategy validation. In the coming days a list of all the solutions available will be on the IDS web.

Concerning the stations network status, 3 situations will be considered:

-       stations that should never be used,

-       stations that should be used partially,

-       stations with breaks in position or velocity at a given epoch (SOLN parameter in the SINEX files).

Each of them corresponds to a given file at ftp://ftp.cls.fr/pub/ids/combinations/ITRF2008-IDS/

There are adapted from the DPOD2005_discontinuities.txt file. There are several motivation for that. One is naturally an update. Another is that the combination software (CATREF-LAREG/IGN) manage the station solution numbers (i.e. breaks) of each series in an homogeneous way which is not the case at the AC level. Also it seems reasonable that no solution number is associated to a period in which data are not used. Finally, several breaks were applied with justification of apparent breaks in time series. For some stations, those unknown breaks have been removed at least provisionally before a more complete investigation with all series.

The main changes are summarizes hereafter. 

/ Updates: REUB & PDMB data not to be used during equipment problems (cable inversion) in 2008

/ Remove unknown breaks:  DIOA/FAIA/KESB/MORB/MSOB/RIPB/ROTA/SPIB/STJB

/ New break: SODA (97.5) in velocity

An open point concern the application of the DORIS USO warming delay which is typically of 4 weeks. From time series coordinates, additional period of datat remove may be applied in several cases (EASB/HKBK/HELA/JIUB/KESB/KITA/KIUB/KRAB/HBMB/KRAB/MATB/MORA/PAQB/RIDA/THUB/SPJB/RIPB/SAKA/SANB).

This issue will also be analyzed with all series, the breaks will then be updated if needed before the weekly combination.

Thanks in advance for any comment or suggestion

Best regards

JJ Valette

 

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   Jean-Jacques VALETTE ([email-masked]) 
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