SUBJ: GPS STATUS 30 MAY 90
1. SATELLITES, PLANES AND CLOCKS (CS=CESIUM RB=RUBIDIUM):
SLOTS MAY NOT BE FINAL UNTIL AFTER 21-SATELLITE REPHASING
A. BLOCK I : PRNS  3,  6,  9, 11, 12, 13
   PLANE   : SLOT D1, A3, A2, C2, A1, C1
   CLOCK   :      RB, RB, RB, CS, CS, CS
B. BLOCK II: PRNS  2, 14, 16, 17, 18, 19, 20
   PLANE   : SLOT B2, E1, D2, F2, F3, A4, B3
   CLOCK   :      CS, CS, RB, CS, CS, CS, CS
2. CURRENT ADVISORIES (ADV) AND FORECASTS (FCST):
INFORMATION IS REPEATED FOR SEVEN DAYS AFTER EVENT CONCLUDES
NANU      MSG DATE/TIME   PRN    TYPE  SUMMARY
099-90136 162101Z MAY 90  PRN12  FCST  CHANGE REPHASE TO 141/2056
                          PRN20  FCST  STATIONKEEPING ON 156/0025
104-90143 231531Z MAY 90  PRN2   FCST  UNUSABLE 145/1200-146/0230
105-90144 241030Z MAY 90  PRN11  ADV   UNUSABLE 144/0844-144/0855
106-90145 251548Z MAY 90  PRN6   ADV   UNUSABLE 145/1500-145/1515
107-90145 251735Z MAY 90  PRN13  ADV   UNUSABLE 145/1700-145/1714
108-90146 261230Z MAY 90  PRN13  ADV   USABLE   146/1047
                          REPORTED AS PRN13 IN ERROR SEE 109-90146
109-90146 261600Z MAY 90  PRN2   ADV   USABLE   146/1047
                          CORRECTION TO #108-90146
110-90147 272000Z MAY 90  PRN12  ADV   UNUSABLE 147/1855-147/1909
111-90147 272100Z MAY 90  PRN11  ADV   UNUSABLE 147/2000-147/2025
112-90149 292300Z MAY 90  PRN3   ADV   UNUSABLE 149/1746-149/1810
113-90149 292315Z MAY 90  PRN6   ADV   UNUSABLE 149/1800-149/1832
114-90150 300620Z MAY 90  PRN6   ADV   UNUSABLE 150/2300-150/0502
3. REMARKS:
A. THE CURRENT GPS CONSTELLATION BEGAN BROADCASTING NAVIGATION
MESSAGES AT ACCURACY LEVELS CONSISTENT WITH STANDARD POSITIONING
SERVICE ON 25 MAR 90. GPS IS NOT EXPECTED TO BE DECLARED FULLY
OPERATIONAL UNTIL 1993. ANY GPS USERS ARE OPERATING AT THEIR OWN
RISK.
4. SATELLITE REPOSITIONING: NOTE ADDITION OF PRN20 TO SCHEDULE
PRN  INITIATE  TERMINATE#1 TERMINATE#2 UNUSABLE (DAY/UTC)
11   15 MAR 90 31 OCT 90                74/0335-75/0225   ACTUAL
 3   20 MAR 90 17 OCT 90                79/0700-79/1220   ACTUAL
13   29 MAR 90  3 OCT 90                88/0142-88/1105   ACTUAL
18    7 APR 90 24 NOV 90   8 DEC 90     97/0318-97/1902   ACTUAL
19   11 APR 90                         101/0421-101/0634  RESCHD
19   12 APR 90 31 DEC 90               102/0440-102/1411  ACTUAL
 9   19 APR 90 19 APR 90               109/2126-110/2126  RESCHD
 9   21 APR 90 21 APR 90               111/1035-111/1440  ACTUAL
16   26 APR 90 20 SEP 90               116/0736-116/1509  ACTUAL
 2    3 MAY 90  1 DEC 90               123/1906-124/0646  ACTUAL
14   14 MAY 90 10 NOV 90               134/0116-134/1013  ACTUAL
12   21 MAY 90 22 MAY 90               141/2230-142/0820  ACTUAL
20    5 JUN 90  6 JUN 90               156/0025-157/0025  FORECAST
5. POINT OF CONTACT: MAJ FAUVER AT (719)550-6379.