SUBJ: GPS STATUS 20 APR 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, CS, RB, CS B. BLOCK II: PRNS 2, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25 PLANE : SLOT B3, E1, D2, E3, D3, F3, A4, B2, E2, E4, D1 A2 CLOCK : CS, CS, CS, CS, CS, CS, CS, CS, CS, CS, CS RB 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 067-92104 131423Z APR 92 PRN11 FCST USABLE NET 107/0000 B. ADVISORIES: NANU MSG DATE/TIME PRN TYPE SUMMARY 068-92105 142252Z APR 92 PRN11 ADV USABLE 105/2145 069-92106 151322Z APR 92 PRN12 ADV UNUSABLE 106/1200-106/1214 070-92106 151723Z APR 92 PRN6 ADV UNUSABLE 106/1710-106/1723 071-92110 191013Z APR 92 PRN6 ADV UNUSABLE 110/0830- UFN 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)554-2634 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