Subject: [SLR-Mail] No. 1279: ESOC Envisat IRVs From: Dirk Kuijper (ESA),Pierre Femenias (ESA),Philip Gibbs (NSGF) > ******************************************************************************** SLR Electronic Mail 2004-11-18 23:51:00 UTC Message No. 1279 ******************************************************************************** Author: Dirk Kuijper (ESA),Pierre Femenias (ESA),Philip Gibbs (NSGF) Subject: ESOC Envisat IRVs As you may have been aware there was a small problem with the IRVs being produced by ESOC for Envisat. This showed itself as a jump in the timebiases at midnight, the timebiases typically running from 0 to -30ms through the day and then resetting to zero at midnight. This then meant that the automatic timebias function generated would be wrong after midnight. Stations using SPADS or requiring small range gates for other reasons would therefore have some trouble acquiring the satellite. This issue was discussed with representatives of the Envisat project from ESRIN at the San Fernando workshop and resulted in a series of communications between ESOC and Herstmonceux on how to improve the IRVs for SLR use. The resulting IRVs are now a much improved product and totally continuous through mid-night. We would strongly recommend that all stations now use the ESOC IRVs for Envisat. Pierre.Femenias@esa.int Dirk.Kuijper@esa.int pgib@nerc.ac.uk From: ”Philip Gibbs” ********************************************************************************