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GPS Satellite PRN 32


Suscrofa
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"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.

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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

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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.

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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 by GPSlug
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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.

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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.

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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.

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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.

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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.

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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 by DENelson83
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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

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