| Date: | 1999-07-12 16:50:00 | |
| Sender: | Roger Wood and Tim Springer <slr@gxvf.rgo.ac.uk (SLR at Herstmonceux)> | |
| Subject: | [SLR-Mail] No. 366: Daily IRVs for GPS and GLONASS satellites | |
| Author: | Roger Wood and Tim Springer | |
| Content: | ******************************************************************************** SLR Electronic Mail 1999-07-12 16:50:00 UTC Message No. 366 ******************************************************************************** Author: Roger Wood and Tim Springer Subject: Daily IRVs for GPS and GLONASS satellites Following requests from several stations this messages announces an extension from 3 days to 5 days in the time span of GPS and GLONASS IRVs produced daily at Herstmonceux from CODE orbits. We hope that this will be of assistance to observers who have FTP access restrictions at weekends or network problems at any time. Details of the derivation, format, filenaming and distribution of these predictions can be found in SLRMAILs 151 and 159. Users of the IRV files should not see any change except for a small increase in file sizes. Similarly the CODE orbit files (COD*.EPH_72, GLO*.EPH_72) and the Earth rotation data files (*.ERP_72) now contain data for 5 days, but the names have not been changed. It should be noted that the quality of the predicted orbits deteriorates rapidly (quadratically) with time. Therefore the performance on day 5 of a prediction will be distinctly less reliable than on day 1, most of the error being along-track. To get the best results users are strongly advised to refresh their holdings each day. From: slr@gxvf.rgo.ac.uk (SLR at Herstmonceux) ******************************************************************************** |