SUBJ: GPS STATUS 18 MAY 92
1. SATELLITES, PLANES AND CLOCKS (CS=CESIUM RB=RUBIDIUM):
A. BLOCK I : PRNS  3,  6, 11, 12, 13
   PLANE   : SLOT C4, A3, C3, A1, C1
   CLOCK   :      RB, RB, RB, RB, CS
B. BLOCK II: PRNS  2, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 28
   PLANE   : SLOT B3, E1, D2, E3, D3, F3, A4, B2, E2, E4, D1  A2, C2
   CLOCK   :      CS, CS, CS, CS, CS, CS, CS, CS, CS, CS, CS  RB, CS
2. CURRENT ADVISORIES (ADV) AND FORECASTS (FCST):
INFORMATION IS REPEATED FOR SEVEN DAYS AFTER EVENT CONCLUDES.
A. FORECASTS:
NANU      MSG DATE/TIME   PRN    TYPE  SUMMARY
121-91182 011354Z JUL 91  BLKII  FCST  SA ON    182/0400- UFN
097-92140 111439Z MAY 92  PRN17  FCST  SCH/MAIN 140/0020- UT 8HRS
B. ADVISORIES:
NANU      MSG DATE/TIME   PRN    TYPE  SUMMARY
098-92134 130708Z MAY 92  PRN3   ADV   UNUSABLE 134/0345-134/0600
099-92137 160740Z MAY 92  PRN3   ADV   UNUSABLE 137/0432-137/0720
100-92137 162030Z MAY 92  PRN3   ADV   UNUSABLE 137/1634-137/1933
101-92138 181458Z MAY 92  PRN13  ADV   UNUSABLE 138/1051-138/1103
102-92138 181511Z MAY 92  PRN3   ADV   UNUSABLE 138/2000-138/2012
3. REMARKS:
A. USERS OF GPS ARE CAUTIONED THAT THE SYSTEM IS NOT YET FULLY
OPERATIONAL. SIGNAL AVAILABILITY AND ACCURACY ARE SUBJECT TO
CHANGE DUE TO AN INCOMPLETE CONSTELLATION AND OPERATIONAL TEST
ACTIVITIES.
B. REF NANU 121 - SELECTIVE AVAILABILITY WAS REACTIVATED AT STANDARD
POSITIONING SERVICE ACCURACY LEVELS ON DAY 182 (01 JUL 91) AT 0400
UTC. VARIATIONS MAY BE SEEN IN THE EFFECT OF SA DURING TESTING, BUT
THE EFFECT SHOULD NOT EXCEED STANDARD POSITIONING SERVICE LEVELS.
THE POINT OF CONTACT IS Lt Col ROB WORLEY (719)554-2634 OR DSN
692-2634.
C. P-CODE WAS UNAVAILABLE BEGINNING DAY 084 (24 MAR 92) AT 2300 UTC
UNTIL DAY 085 AT 0100 UTC, AGAIN ON DAY 085 AT 2300 UTC UNTIL DAY
086 AT 0100 UTC, AND AGAIN ON DAY 086 AT 2300 UNTIL DAY 087 (27
MAR 92) AT 0100 UTC. THROUGHOUT THIS TIME STANDARD POSITIONING
SERVICE WAS AVAILABLE USING C/A-CODE THROUGHOUT THESE TIMES.
4. POINTS OF CONTACT:
A. CIVILIAN: US COAST GUARD AT COMMERCIAL (703)866-3806 VOICE OR
(703)866-3890 COMPUTER BBS.
B. MILITARY: 2SOPS/DOAI 1LT SKINNER AT (719)550-6378/80 OR DSN 560-
6378/80