SUBJ: GPS STATUS 18 JUN 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
119-90162 110530Z JUN 90  PRN6   ADV   UNUSABLE 162/0421-162/0441
120-90163 121338Z JUN 90  PRN17  FCST  UNUSABLE 165/1030-166/0430
121-90165 141806Z JUN 90  PRN20  FCST  UNUSABLE 166/2000-167/0400
122-90166 160100Z JUN 90  PRN3   ADV   UNUSABLE 166/2300-166/2340
123-90168 170546Z JUN 90  PRN6   ADV   UNUSABLE 168/0520-168/0545
3. REMARKS:
A. IMPLEMENTATION OF STANDARD POSITIONING SERVICE:
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.
B. NOTICE ADVISORY INFORMATION WILL NOT BE AVAILABLE DIRECTLY FROM
THE MASTER CONTROL STATION FOR CIVIL USERS BEGINNING 1 AUG 90. THIS
INFORMATION MAY BE OBTAINED FROM THE US COAST GUARD, THE GENERAL
DYNAMICS GPS BULLETIN BOARD, AND THE US NAVAL OBSERVATORY.
C. SATELLITE REPOSITIONING:
THE SATELLITES WHICH BEGAN REPOSITIONING EARLIER THIS YEAR WILL
CONTINUE GRADUAL CHANGES TO THEIR ORBITAL POSITIONS UNTIL
REPOSITIONING TERMINATE DATES AS SHOWN BELOW:
PRN  TERMINATE#1 TERMINATE#2  REMARKS
11   31 OCT 90                FINAL MANEUVER
 3   17 OCT 90                FINAL MANEUVER
13    3 OCT 90                FINAL MANEUVER
18   24 NOV 90   8 DEC 90     24 NOV 90 WILL SLOW THE RATE OF CHANGE
19   31 DEC 90                FINAL MANEUVER
16   20 SEP 90                FINAL MANEUVER
 2    1 DEC 90                FINAL MANEUVER
14   10 NOV 90                FINAL MANEUVER
4. POINT OF CONTACT: MAJ FAUVER AT (719)550-6379.