Ref: http://WWW.SCHRIEVER.AF.MIL/GPS/Current/current.nnu?
http://WWW.SCHRIEVER.AF.MIL/GPS/Current/current.oa1?
http://www.navcen.uscg.gov/gps/geninfo/NANUabbr.htm


NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2007001
SUBJ: SVN25 (PRN25) FORECAST OUTAGE CANCELLED
1. NANU TYPE: FCSTCANC
NANU NUMBER: 2007001
NANU DTG: 042022Z JAN 2007
REFERENCE NANU: 2006167
REF NANU DTG: 281727Z DEC 2006
SVN: 25
PRN: 25
START JDAY: 004
START TIME ZULU: 2027
START CALENDAR DATE: 04 JAN 2007
STOP JDAY: CANCELLED
STOP TIME ZULU: N/A
STOP CALENDAR DATE: N/A

2. CONDITION: THE FORECAST OUTAGE FOR GPS SATELLITE SVN25 (PRN25)
SCHEDULED FOR
JDAY 004 (04 JAN 2007) BEGINNING 2027 ZULU HAS BEEN CANCELLED.

3. 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, SPACEAF.AOC@VANDENBERG.AF.MIL


UNCLASSIFIED
GPS OPERATIONAL ADVISORY 004.OA1
SUBJ: GPS STATUS 04 JAN 2007

1. SATELLITES, PLANES, AND CLOCKS (CS=CESIUM RB=RUBIDIUM):
A. BLOCK I : NONE
B. BLOCK II: PRNS 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14
PLANE : SLOT F6, D1, C2, D4, B4, C1, C5, A3, A1, E3, D2, B5, F3, F1
CLOCK : CS, RB, RB, RB, RB, RB, RB, CS, RB, CS, RB, RB, RB, RB
BLOCK II: PRNS 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28
PLANE : SLOT D5, B1, C4, E4, C3, E1, D3, E2, F4, D6, A5, F2, A4, B3
CLOCK : RB, RB, RB, RB, RB, RB, RB, RB, RB, CS, RB, RB, CS, RB
BLOCK II: PRNS 29, 30, 31
PLANE : SLOT F5, B2, A2
CLOCK : RB, CS, 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)

2006159 112154Z DEC 2006 05 FCSTDV 349/2100-350/0900
2006160 112202Z DEC 2006 08 FCSTDV 353/0700-353/1900
2006162 152024Z DEC 2006 17 FCSTDV 354/1400-355/0600
2006163 160556Z DEC 2006 05 FCSTSUMM 349/2127-350/0553
2006164 191214Z DEC 2006 08 FCSTSUMM 353/0805-353/1213
2006165 201613Z DEC 2006 17 FCSTSUMM 354/1431-354/1607
2006167 281727Z DEC 2006 25 FCSTDV 005/0730-006/0730
2007001 042022Z JAN 2007 25 FCSTCANC 004/2027-/
B. ADVISORIES:
NANU MSG DATE/TIME PRN TYPE SUMMARY (JDAY/ZULU
TIME START - STOP)

2006161 130309Z DEC 2006 12 USABINIT 347/0307-/
2006166 270145Z DEC 2006 03 UNUSUFN 361/0120-/
C. GENERAL:
NANU MSG DATE/TIME PRN TYPE SUMMARY (JDAY/ZULU
TIME START - STOP)

2006155 062348Z DEC 2006 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 (703)313-5900 24 HOURS DAILY AND INTERNET
HTTP://WWW.NAVCEN.USCG.GOV
C. MILITARY SUPPORT WEBPAGES CAN BE FOUND AT THE FOLLOWING
HTTP://GPS.AFSPC.AF.MIL/GPS OR HTTP://GPS.AFSPC.AF.MIL/GPSOC

Why is it that in these reports (and other such NAVSTAR status reports) that
the clock types (RB versus CS) are reported? Is there something about the
clock type that, as a GPS user, I would be concerned about?

I don't have any particular reason for asking this, just curious.