From Ulf Fri Apr 1 13:07:45 1994 From: Ulf (Ulf) Date: Fri, 1 Apr 1994 13:07:45 PST Subject: [IGSMAIL-0553] GPS Global Network Advisory Message-ID: IGS Electronic Mail Fri Apr 1 13:07:45 PST 1994 Message Number 0553 ****************************************************************************** Author: Ulf J. Lindqwister/JPL Subject: GPS Global Network Advisory: Rogue Firmware Upgrade Status Subject: GPS Global Network Advisory: Rogue Firmware Upgrade Status Dear Colleagues, The Rogue receiver firmware version 7.5 definitivly has one or more software bugs in it. An analysis of the data volume collected from Rogue receivers running versions 7.3 and 7.5 and from TurboRogues before and after AS came on (January 31, 94) shows the following: Receiver Software # Stations Before AS After AS Loss ----------------------------------------------------------------- Rogue V7.3 7 95% 93% 2% V7.5 18 94% 81% 13% TurboRogue V2.8 15 94% 90% 4% ----------------------------------------------------------------- The Rogue V7.3 and TurboRogue data losses are essentially equivalent (within the error bars) and are due to data acquisition and loss of lock for satellites at generally higher elevation angels when AS is on (AS data has lower SNR). The 13% data loss for receivers with the latest Rogue software (V7.5) can only be a software bug. The data loss is not uniform, were 75% data loss in all receivers (with V7.5) for a few days are followed by 2-3 weeks of 95% data and then the receivers drop to 75% again, in a 2-3 week repeating pattern. Version 7.5 had several bugs fixed and some added featurers (one of which we believe is causing the data loss). We have decided to remove the feature causing the data loss are currently testing Version 7.7. The new version (7.7) is expected to be released 1 month from now. For now we suggest the following solutions: 1. Switch the Rogue to a TurboRogue (if possible). For those of you who have TurboRogues you will get more data at higher quality compared the Rogues. Also, the Rogues owned by NASA are being faced out and eventually the software in the Rogue will not be supported. (the faceout period has been decied yet). 2. Switch back to Version 7.3. If you don't care about the pseudorange data, then you are better off with 7.3 right now. - Ulf ======================================================================= Ulf J. Lindqwister Telephone: (818) 354 1734 GPS Networks & Operations Group FAX: (818) 393 4965 Jet Propulsion Laboratory Email: ujl at logos.jpl.nasa.gov 4800 Oak Grove Dr. Pasadena, CA 91109 =======================================================================