On Jul 20, 11:37*pm, Sam Wormley <sworml...@gmail.com> wrote:
> http://www.navcen.uscg.gov/gps/genin...S/status/2011/
>
>
>
>
>
>
>
>
>
> > NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2011048 NANU TYPE: GENERAL
> > *** GENERAL MESSAGE TO ALL GPS USERS ***
> > GPS SATELLITE SVN30 (PRN30) WAS DECOMMISSIONED FROM ACTIVE SERVICE ON JDAY 201 (20 JUL 2011). *PRN30 WILL BE AVAILABLE FOR FUTURE SATELLITE SERVICE.
> > *** GENERAL MESSAGE TO ALL GPS USERS ***
>
> > * *POC: CIVILIAN - NAVCEN AT 703-313-5900, HTTPS://WWW.NAVCEN.USCG.GOV
> > * *MILITARY - GPS OPERATIONS CENTER at HTTP://GPS.AFSPC.AF.MIL/GPSOC, DSN 560-2541,
> > * *COMM 719-567-2541, gps_supp...@schriever.af.mil, HTTPS://gps.afspc.af.mil
> > * *MILITARY ALTERNATE - JOINT SPACE OPERATIONS CENTER, DSN * *276-3514,
> > * *COMM 805-606-3514, JSPOCCOMBAT...@VANDENBERG.AF.MIL
>
> > GPS OPERATIONAL ADVISORY * * * *201.OA1
> > SUBJ: GPS STATUS 20 JUL 2011
> > 1. SATELLITES, PLANES, AND CLOCKS (CS=CESIUM RB=RUBIDIUM):
> > A. BLOCK I : NONE
> > B. BLOCK II: PRNS *1, *1, *2, *3, *4, *5, *6, *7, *8,*9, 10, 11, 12, 13
> > * *PLANE * : SLOT B6, D6, D1, C2, D4, E6, C6, A4, A3, A1, E6, D2,B4, F3
> > * *CLOCK * : * * *RB, CS, RB, CS, RB, RB, RB, RB, CS, CS, CS, RB, RB, RB
> > * *BLOCK II: PRNS 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27
> > * *PLANE * : SLOT F1, F2, B1, C4, E4, C3, E1, D3, E2, F4, D5, B2,F5, A6
> > * *CLOCK * : * * *RB, RB, RB, RB, RB, RB, RB, RB, RB, RB, CS, RB, RB, CS
> > * *BLOCK II: PRNS 28, 29, 30, 31, 32
> > * *PLANE * : SLOT B3, C1, B5, A2, E5
> > * *CLOCK * : * * *RB, RB, CS, RB, RB
> > 2. CURRENT ADVISORIES AND FORECASTS :
> > A. FORECASTS: * * * * * FOR SEVEN DAYS AFTER EVENT CONCLUDES.
> > NANU * * * * *MSG DATE/TIME * * * PRN *TYPE * * * * SUMMARY (JDAY/ZULU TIME START - STOP)
> > B. ADVISORIES:
> > NANU * * * * *MSG DATE/TIME * * * PRN *TYPE * * * * SUMMARY (JDAY/ZULU TIME START - STOP)
> > 2011042 * * * 132058Z May 2011 * *30 * UNUSUFN * * *133/2055-/
> > C. GENERAL:
> > NANU * * * * *MSG DATE/TIME * * * PRN *TYPE * * * * SUMMARY (JDAY/ZULU TIME START - STOP)
> > 2011045 * * * 222019Z Jun 2011 * * * * GENERAL * * */-/
> > 2011046 * * * 122307Z Jul 2011 * * * * GENERAL * * */-/
> > 2011047 * * * 160718Z Jul 2011 * *01 * LAUNCH * * * /-/
> > 2011048 * * * 210140Z Jul 2011 * * * * GENERAL * * */-/
> > 3. REMARKS:
> > A. THE POINT OF CONTACT FOR GPS MILITARY OPERATIONAL SUPPORT IS THE GPS
> > OPERATIONS CENTER AT 719-567-2541 OR DSN 560-2541.
> > B. CIVILIAN: *FOR INFORMATION, CONTACT US COAST GUARD NAVCEN AT
> > COMMERCIAL 719-567-2541 24 HOURS DAILY AND INTERNET
> > HTTPS://WWW.NAVCEN.USCG.GOV
> > C. MILITARY SUPPORT WEBPAGES CAN BE FOUND AT THE FOLLOWING
> > HTTPS://gps.afspc.af.mil/GPS OR HTTPS://gps.afspc.af.mil/GPSOC
This marks the retirement of the last IIA bird on the most demanding
orbital plane, the B plane.
It's the most demanding due to thermal and power cycles caused by
solar eclipses (that was the explanation for IIF-1 not performing much
better than IIR-M birds, correct me if appropriate).
There are healthy IIA birds operational on all other orbits A-3, C-2,
D-2, E-2, F-1, not counting the residuals.
The next oldest bird on the B plane is IIR-5 (SVN44), that completed
11 years since launch last week. Hence it's close to 4 years past its
expected (let's call it minimum) service life. In 5 months the oldest
operational bird IIA-10 (SVN23) will complete 21 years, to this date
it's ephemeris and clock performance is excellent considering it's
almost years too old :-)
Take that GAO and your pessimistic views... GAO, the "problem" with
the GPS constellation isn't that satellites will die out of a
sudden... It's that they are living a long geriatric life (both great
and bad), which will slow L2C and L5 signals becoming operational by
10+ years each. Certainly not the alarmist chaos scenario that you've
been making a big deal out of.
But that certainly is causing the GPS constellation to perform way
better than specs. If GPS birds were dying within a few years of their
projected service life, we might be stuck with 24 or so operational
satellites, instead of the current 30/31 operational, without 32
operational just because of control segment limitations...
Marcelo Pacheco
Similar Threads
Linear Mode
