IGS Analysis Center Workshop - IGS - NASA

1) I(X3 PROCESSING/REPORTS/FORMATSSP3 will be the format of initial IGS orbit products; all Analysis Centers should comply NOLATER THAN January 1, 1994. Orbit files will contain SV clocks (either broadcast or precise) atsame frequency as ephemeris..The IGS Central Bureau (CB) is to coordinate the preparation of EOP and Summary formats basedon issues raised during discussion. Time frame: end of November, mid- December. A separateformat for higher-frequency precise SV clocks is required (format to be determined, and to beapplicable to station clocks as well). Work to begin on the new format, with possibility that orbitsand clocks can coexist in same file at different frequencies; CB is to coordinate e-mail discussionon the possible clock and orbit format.Each of the following stations is currently used as a fiducial (coordinates are held fixed or tightlyconstrained) by a majority of Analysis Centers; data from sites denoted by * may be a concern intwo ways: timeliness of data such as the DSN sites or discrepancies in the site tie information:Algonquin ParkFairbanksGoldstone*Hartebeesthoek*Kokee ParkKootwijkMadrid*SantiagoTromsoTidbinbilla*WettzellYarragadeeYellowknifePropose that coordinates of all of the above stations (with possible exception of the * sites) be fixedor tightly constrained by all Analysis Centers in their production of the orbit product and that allCenters use the same set of coordinates and velocities for the above sites2) IGS ORBIT PRODUCTSAll Analysis Centers are encouraged to submit their products as soon as possible (daily) but notlater than two weeks from the date of observation. When all Center orbits are received, or after thetwo week period whichever comes first, an IGS combined orbit product will be generated.Two IGS orbit products will be generated based on principles developed in the position paper 2:- ‘Rapid orbit product’ consistent with IERS Rapid Service (Bull. A), and available within twoweeks.- ‘Final (archive) orbit product’ consistent with the final IERS (Bull. B) pole values and available.100