SUBJ: GPS STATUS 2 AUG 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
126-90172 211629Z JUN 90  ALLSV  FCST  TESTING  175/0000-240/0000
147-90207 262200Z JUL 90  PRN11  ADV   UNUSABLE 207/2100-207/2114
148-90208 270100Z JUL 90  PRN16  FCST  UNUSABLE 212/2200-213/1600
149-90209 291000Z JUL 90  PRN11  ADV   UNUSABLE 209/1500-209/1515
150-90213 012126Z AUG 90  PRN6   FCST  WARNING  214/0000-224/0000
151-90213 012300Z AUG 90  PRN11  ADV   UNUSABLE 213/2200-213/2235
152-90214 021400Z AUG 90  PRN6   ADV   UNUSABLE 214/1200-214/1214
3. REMARKS:
A. NAVIGATION SIGNAL (L1 AND L2) BROADCASTS FROM PRN6 MAY BE
INTERRUPTED WITHOUT WARNING DURING THE PERIOD 214/0000-224/0000.
ADVISORIES WILL BE AVAILABLE AS SOON AS POSSIBLE FOLLOWING THE
OUTAGE. AVOID USING PRN6 DURING THIS PERIOD, IF POSSIBLE.
B. 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.
C. 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
D. LIMITED SELECTIVE AVAILABILITY TESTING CONDUCTED DURING THE
PERIOD BEGINNING DAY 174 (24 JUN 90) UNTIL DAY 240 (28 AUG 90)
SHOULD NOT DEGRADE NAVIGATION ACCURACY BEYOND LEVELS IN EFFECT
SINCE THE IMPLEMENTATION OF THE STANDARD POSITIONING SERVICE.
HOWEVER, USERS MAY OBSERVE SOME CHANGES IN DAY-TO-DAY POSITIONING
AND NAVIGATION ACCURACY AS A RESULT OF THIS TEST. POINT OF CONTACT
IS MAJOR WYSOCKI AT USSPACECOM/SPJ3OS, (719)554-2634 OR AUTOVON
692-2634.
4. POINT OF CONTACT: MAJ FAUVER AT (719)550-6379.