Suscrofa Posted April 8, 2007 Share Posted April 8, 2007 This morning 08:00 Paris time and location, I was really surprised to see on my 60CX a PRN 32 satellite ! It was at the horizon and got lost after about half an hour. Funny, I never saw it before and it looks from here: http://sidt.gpsworld.com/gpssidt/article/a...l.jsp?id=396031 that it is an old one reinstated for test purpose. I know at least that the 60CX can handle up to PRN 32 Quote Link to comment
+EraSeek Posted April 8, 2007 Share Posted April 8, 2007 "the most pressing concern is with potential impacts to existing fielded GPS receivers that may not properly account for up to 32 operational PRNs." The early December and January L-band broadcasts by SVN 23 may represent tests to assess various aspects of that future eventuality." Guess we are the guinea pigs. Quote Link to comment
+EraSeek Posted April 9, 2007 Share Posted April 9, 2007 Yes, I am seeing it right now. On my screen it is at the top (north) which often means it is broadcasting but not in the almanac as it is in an unhealthy test mode. Quote Link to comment
+EraSeek Posted April 9, 2007 Share Posted April 9, 2007 NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2007051 NANU TYPE: GENERAL *** GENERAL MESSAGE TO ALL GPS USERS *** ON 2 APR 2007, SVN23 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN32. AT L-BAND ACTIVATION, SVN23/PRN32 WILL BE UNUSABLE UNTIL FURTHER NOTICE. ADDITIONALLY, NO BROADCAST ALMANACS WILL INCLUDE SVN23/PRN32. FUTURE NANUS WILL NOTIFY USERS OF ANY CHANGES TO THE ABOVE-STATED STATUS. ANYONE EXPERIENCING PROBLEMS WITH PRN32 SHOULD CONTACT THE APPROPRIATE AGENCY LISTED BELOW. POC: CIVILIAN: NAVCEN AT COMM 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV MILITARY: GPS OPERATIONS CENTER AT DSN 560-2541 OR COMM 719-567-2451, HTTP://GPS.AFSPC.AF.MIL/GPSOC/ MILITARY ALTERNATE: JOINT SPACE OPERATIONS CENTER, DSN 276-9994 OR COMM 805-606-9994, EMAIL: JSPOCCOMBATOPS@VANDENBERG.AF.MIL Quote Link to comment
+buddles Posted June 22, 2007 Share Posted June 22, 2007 NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2007051 NANU TYPE: GENERAL *** GENERAL MESSAGE TO ALL GPS USERS *** ON 2 APR 2007, SVN23 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN32. ... ANYONE EXPERIENCING PROBLEMS WITH PRN32 SHOULD CONTACT THE APPROPRIATE AGENCY LISTED BELOW.... POC: CIVILIAN: NAVCEN AT COMM 703-313-5900, When GPS receivers were first being built, some manufacturers numbered them from 0 to 31. Others numbered them from 1 to 32. This is the reason for the "anyone experiencing problems with PRN32" comment. They want to know if this is still an issue. I just completed a study for GPS Wing on what it would take to update the GPS Signal Specification ICD-GPS-200D to handle more than 32 satellites in the constellation. Quote Link to comment
+DENelson83 Posted September 12, 2007 Share Posted September 12, 2007 (edited) I'm seeing PRN 32 on my GPSMAP 76CSx too, and boy, was I surprised when I initially caught sight of it on the satellite screen. I guess a NANU has not yet been issued announcing its usability. Edited September 12, 2007 by DENelson83 Quote Link to comment
+GPSlug Posted September 12, 2007 Share Posted September 12, 2007 (edited) 32 is in the almanac now, but set unhealthy. ******** Week 420 almanac for PRN-32 ********ID: 32 Health: 063 Eccentricity: 0.1486301422E-001 Time of Applicability(s): 405504.0000 Orbital Inclination(rad): 0.9727499482 Rate of Right Ascen(r/s): -0.7966046104E-008 SQRT(A) (m 1/2): 5153.497559 Right Ascen at Week(rad): -0.6794422604E+000 Argument of Perigee(rad): -1.383111755 Mean Anom(rad): -0.5137318886E+000 Af0(s): 0.5722045898E-004 Af1(s/s): 0.1818989404E-010 week: 420 That's why your GPSr knows to look for it, but not use it. If I force a receiver to track and use it, it works perfectly fine. There's no problem with the data or signal. But that's exactly why it's turned on but unhealthy; so manufacturers can test it without breaking current users. Edited September 12, 2007 by GPSlug Quote Link to comment
+DENelson83 Posted September 12, 2007 Share Posted September 12, 2007 32 is in the almanac now, but set unhealthy. ******** Week 420 almanac for PRN-32 ********ID: 32 Health: 063 Eccentricity: 0.1486301422E-001 Time of Applicability(s): 405504.0000 Orbital Inclination(rad): 0.9727499482 Rate of Right Ascen(r/s): -0.7966046104E-008 SQRT(A) (m 1/2): 5153.497559 Right Ascen at Week(rad): -0.6794422604E+000 Argument of Perigee(rad): -1.383111755 Mean Anom(rad): -0.5137318886E+000 Af0(s): 0.5722045898E-004 Af1(s/s): 0.1818989404E-010 week: 420 That's why your GPSr knows to look for it, but not use it. That's the thing. My GPSr was showing PRN 32 on the satellite page, with a solid bar, which means it is using the PRN 32 signal to compute its fix. That tells me PRN 32 has just been set healthy. Quote Link to comment
+GPSlug Posted September 12, 2007 Share Posted September 12, 2007 That's the thing. My GPSr was showing PRN 32 on the satellite page, with a solid bar, which means it is using the PRN 32 signal to compute its fix. That tells me PRN 32 has just been set healthy. That's most likely a subtlety in the meaning of the solid bar. It could just mean that it's received the ephemeris and would be able to use it in the solution if it was healthy. Is 32 still showing as due north and right on the horizon while this is happening? At any rate, I'll take a look again when 32 comes back up. Quote Link to comment
+EraSeek Posted September 13, 2007 Share Posted September 13, 2007 Yes it is due north and on the horizon on the sat page, and has been there every morning for some time, which I believe indicates that it is in test mode. Quote Link to comment
+GPSlug Posted September 13, 2007 Share Posted September 13, 2007 Yes it is due north and on the horizon on the sat page, and has been there every morning for some time, which I believe indicates that it is in test mode. The health bits in both the almanac and it's ephemeris indicate that the Navigation data for it is bad. Basically it's saying, "I don't where I am" so the GPSr shows it in a default location. So the solid bar can't actually be indicating that 32 is being used in the solution, just that the ephemeris has been received. Quote Link to comment
+Egnix Posted September 13, 2007 Share Posted September 13, 2007 Yes it is due north and on the horizon on the sat page, and has been there every morning for some time, which I believe indicates that it is in test mode. Remember that the GPS satellites are orbiting the earth at a pace of about 2 times a day. There's some drift, but esentially the bird should be in roughly the same area every day I believe. This is just it's orbital plane. It has nothing to do with it being in a "test" mode. Quote Link to comment
+EraSeek Posted September 14, 2007 Share Posted September 14, 2007 Yes it is due north and on the horizon on the sat page, and has been there every morning for some time, which I believe indicates that it is in test mode. Remember that the GPS satellites are orbiting the earth at a pace of about 2 times a day. There's some drift, but esentially the bird should be in roughly the same area every day I believe. This is just it's orbital plane. It has nothing to do with it being in a "test" mode. No, whenever there is a problem with the data on a sat that the 60cx can see, it is always placed at the very top of the sat status page, no matter where it is in the sky. Quote Link to comment
+DENelson83 Posted September 14, 2007 Share Posted September 14, 2007 whenever there is a problem with the data on a sat that the 60cx can see, it is always placed at the very top of the sat status page, no matter where it is in the sky. Because that's an azimuth of 0° and an elevation of 0°. Quote Link to comment
+Egnix Posted September 15, 2007 Share Posted September 15, 2007 No, whenever there is a problem with the data on a sat that the 60cx can see, it is always placed at the very top of the sat status page, no matter where it is in the sky. Sorry about that. Quote Link to comment
+DENelson83 Posted February 8, 2008 Share Posted February 8, 2008 (edited) NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2008016 NANU TYPE: GENERAL *** GENERAL MESSAGE TO ALL GPS USERS *** THE GPS COMMUNITY GAINED APPROVAL TO SET SVN23 (PRN32) USABLE. BASED ON CURRENT PLANNING, SVN23 (PRN32) WILL BE SET USABLE ON JDAY 050 (19 FEB 2008). AN ADDITIONAL NANU WILL TRANSMIT NLT 4 DAYS PRIOR TO THE PROJECTED USABLE DATE/TIME. IF NECESSARY, ADDITIONAL NANUS WILL NOTIFY USERS OF ANY CHANGES TO THIS PLAN. ANYONE EXPERIENCING PROBLEMS OR HAVING ANY CURRENT CONCERNS WITH PRN32 SHOULD CONTACT THE APPROPRIATE AGENCY LISTED BELOW. POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV MILITARY - GPS OPERATIONS CENTER AT HTTP://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541, COMM 719-567-2541, GPS_SUPPORT@SCHRIEVER.AF.MIL, HTTP://GPS.AFSPC.AF.MIL/GPS MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-9994, COMM 805-606-9994, JSPOCCOMBATOPS@VANDENBERG.AF.MIL *** GENERAL MESSAGE TO ALL GPS USERS *** Edited February 8, 2008 by DENelson83 Quote Link to comment
+DENelson83 Posted February 27, 2008 Share Posted February 27, 2008 NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2008024 NANU TYPE: GENERAL *** GENERAL MESSAGE TO ALL GPS USERS *** GPS SATELLITE SVN23 (PRN32) WAS USABLE AS OF JDAY 057 (26 FEB 2008) BEGINNING 1801 ZULU. *** GENERAL MESSAGE TO ALL GPS USERS *** POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTP://WWW.NAVCEN.USCG.GOV MILITARY - GPS OPERATIONS CENTER at HTTP://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541, COMM 719-567-2541, gps_support@schriever.af.mil, HTTP://gps.afspc.af.mil/gps MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN 276-9994, COMM 805-606-9994, JSPOCCOMBATOPS@VANDENBERG.AF.MIL Quote Link to comment
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