Subject: [SLR-Mail] No. 1241: Summary Status CHAMP SLR Tracking From: R. Schmidt, R. Koenig, GeoForschungsZentrum Potsdam > ******************************************************************************** SLR Electronic Mail 2004-07-23 23:54:00 UTC Message No. 1241 ******************************************************************************** Author: R. Schmidt, R. Koenig, GeoForschungsZentrum Potsdam Subject: Summary Status CHAMP SLR Tracking Dear colleagues, please be informed on the results of our query on CHAMP SLR Tracking initiated in SLRMail No. 1229. From the given responses we may conclude that CHAMP predictions are in general still sufficiently accurate for tracking and we do not need to increase the current update rate of 3 predicts/day. The sub-daily updates are used at the majority of the ILRS stations, which is a prerequiste for successfull tracking. Part of the recent reduction of SLR data for CHAMP could be explained by stations having problems in day-light tracking in connection with the visibility cycle of CHAMP. Another portion could be due to the reduced activity of NASA-funded SLR stations. At GFZ we´ll continue to monitor the quality/aging of our predicts via comparisons to precise CHAMP orbits. Also, we´ll do experiments using latest GRACE gravity field solutions which might further improve the aging of the predicts allowing to stick to the current update rate even longer. At this point we´ld like to thank all the stations/operators for their contributions. Best regards, Roland Schmidt Rolf Koenig From: Roland Schmidt ********************************************************************************