SUBJ: GPS STATUS 28 OCT 91
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, CS, CS, CS
B. BLOCK II: PRNS  2, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24
   PLANE   : SLOT B3, E1, D2, E3, D3, F3, A4, B2, E2, E4, D1
   CLOCK   :      CS, CS, CS, CS, CS, CS, CS, CS, CS, CS, 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
180-91301 181919Z OCT 91  PRN20  FCST  UNUSABLE 301/1415-UP TO 8 HRS
186-91304 251847Z OCT 91  PRN20  FCST  UNUSABLE 304/1145-UP TO 11 HRS
B. ADVISORIES:
NANU      MSG DATE/TIME   PRN    TYPE  SUMMARY
184-91297 240500Z OCT 91  PRN6   ADV   UNUSABLE 297/0354-UFN
185-91297 241000Z OCT 91  PRN6   ADV   USABLE 297/0457
187-91300 272015Z OCT 91  PRN17  ADV   UNUSABLE 300/1800-UFN
188-91301 281501Z OCT 91  PRN17  ADV   USABLE 301/0410
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 MAJ ROB WORLEY (719)554-5770 OR DSN
692-5770.
4. POINTS OF CONTACT:
A. CIVILIAN: US COAST GUARD AT COMMERCIAL (703)866-3806 VOICE OR
(703)866-3890 COMPUTER BBS.
B. MILITARY: 2SCS/DOCI LT INGEGNERI AT (719)550-6379 OR DSN 560-6379