GPS CONSTELLATION STATUS -- Wed Sep 28 12:06:44 UTC 2005
UNITED STATES NAVAL OBSERVATORY (USNO)
GPS CONSTELLATION STATUS
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Information in this file is retained for approximately seven
days or until completion of the event; be aware that the
information provided below may change.
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A. BLOCK II/IIA/IIR/IIR-M INDIVIDUAL SATELLITE STATUS
SVN PRN
15 15 Launched 01 OCT 1990; usable 15 OCT 1990; operating on Cs std
24 24 Launched 04 JUL 1991; usable 30 AUG 1991; operating on Cs std
25 25 Launched 23 FEB 1992; usable 24 MAR 1992; operating on Cs std
Unusable 28 Sep 0435 UT and will remain unusable until
further notice (NANU 2005124)
26 26 Launched 07 JUL 1992; usable 23 JUL 1992; operating on Rb std
27 27 Launched 09 SEP 1992; usable 30 SEP 1992; operating on Rb std
29 29 Launched 18 DEC 1992; usable 05 JAN 1993; operating on Rb std
30 30 Launched 12 SEP 1996; usable 01 OCT 1996; operating on Rb std
31 31 Launched 30 MAR 1993; usable 13 APR 1993; operating on Rb std
Unusable 14 Apr 1634 UT and will remain unusable until
further notice (NANU 2005055)
32 01 Launched 22 NOV 1992; usable 11 DEC 1992; operating on Cs std
33 03 Launched 28 MAR 1996; usable 09 APR 1996; operating on Cs std
34 04 Launched 26 OCT 1993; usable 22 NOV 1993; operating on Rb std
35 05 Launched 30 AUG 1993; usable 28 SEP 1993; operating on Cs std
36 06 Launched 10 MAR 1994; usable 28 MAR 1994; operating on Rb std
37 07 Launched 13 MAY 1993; usable 12 JUN 1993; operating on Rb std
38 08 Launched 06 NOV 1997; usable 18 DEC 1997; operating on Cs std
39 09 Launched 26 JUN 1993; usable 20 JUL 1993; operating on Cs std
40 10 Launched 16 JUL 1996; usable 15 AUG 1996; operating on Cs std
41 14 Launched 10 NOV 2000; usable 10 DEC 2000; operating on Rb std
43 13 Launched 23 JUL 1997; usable 31 JAN 1998; operating on Rb std
44 28 Launched 16 JUL 2000; usable 17 AUG 2000; operating on Rb std
45 21 Launched 31 MAR 2003; usable 12 APR 2003; operating on Rb std
46 11 Launched 07 OCT 1999; usable 03 JAN 2000; operating on Rb std
47 22 Launched 21 DEC 2003; usable 12 JAN 2004; operating on Rb std
51 20 Launched 11 MAY 2000; usable 01 JUN 2000; operating on Rb std
53 17 Launched 26 SEP 2005 (NANU 2005123/26 SEP)
For more information about PRN17/SVN53, see:
http://www.spaceflightnow.com/delta/d313a/
54 18 Launched 30 JAN 2001; usable 15 FEB 2001; operating on Rb std
56 16 Launched 29 JAN 2003; usable 18 FEB 2003; operating on Rb std
59 19 Launched 20 MAR 2004; usable 05 APR 2004; operating on Rb std
Unusable 27 Sep 1115 UT to 28 Sep 0546 UT due to
maintenance (NANUs 2005122, 28 SEP)
60 23 Launched 23 JUN 2004; usable 09 JUL 2004; operating on Rb std
61 02 Launched 06 NOV 2004; usable 22 NOV 2004; operating on Rb std
B. GPS ACTIVITIES
1. Scheduled Coordinated Universal Time (UTC) Time Step (Leap Second)
The International Earth Rotation and Reference Systems service (IERS)
has announced the introduction of a time step to occur at the end of
December, 2005. Coordinated Universal Time (UTC) will be retarded
by 1.0s so that the sequence of dates of the UTC markers will be:
2005 December 31 23h 59m 59s
2005 December 31 23h 59m 60s
2006 January 01 0h 0m 0s
UTC and all time scales based on UTC will be affected by this
adjustment. However, GPS will not be adjusted physically. For GPS,
the leap second correction contained within the UTC data of subframe 4,
page 18 of the navigation message transmitted by satellites will change.
Before the leap second
GPS-UTC = +13s (i.e. GPS is ahead of UTC by thirteen seconds)
After the leap second
GPS-UTC = +14s (i.e. GPS is ahead of UTC by fourteen seconds)
2. Selective Availablility (SA) levels set to zero.
On May 2, 2000 at 0400 UT, SA levels were set to zero. For more
details, check the Interagency GPS Executive Board (IGEB) web
site at http://www.igeb.gov.
3. Coordinated Universal Time (UTC) Time Step (Leap Second)
As of January 1, 1999, 0H 0M 0S, GPS is AHEAD of UTC by
THIRTEEN (+13) seconds.
4. GPS Automatic Time Steering
In effect 18 Mar 1994 at 1415 UT and will remain in effect until
further notice at rate +/-1.0E-19 seconds per second squared.
5. Activation of Anti-Spoof (A-S)
A-S was activated January 31, 1994 at 0000 UTC. Due to the
December 8, 1993 declaration of Initial Operational Capability
(IOC), the P-code will not normally be available to users who
do not have valid cryptographic keys (iaw Federal Radionavigation
Plan (FRP) 1992). (NANU 050-94042/DTG 112045Z FEB 94)
6. Implementation of Selective Availability (SA)
a. SA was reactivated on July 1, 1991 at 0400 UT and will remain in
effect until further notice. Civil users will receive Standard
Positioning Service (SPS) accuracy as specified in the Federal
Radionavigation Plan (FRP). POC for policy: CDR Jackson at
DSN 692-2634 or (719) 554-2634. (NANU 121-91182/DTG 011354Z JUL 91)
b. According to the 2nd Satellite Operations Squadron (2SOPS)
Operational Advisory Bulletin: SA was implemented on November 15,
1991 to the SPS level.
7. Change to GPS Broadcast Navigation Message
On June 2, 1995 beginning approximately 1900 UT, the GPS Master
Control Station began adding data to the spare data fields in
the broadcast navigation message. The navigation message will
be in full compliance with existing message structure agreements
outlined in ICD-GPS-200C and the GPS Standard Positioning Service
(SPS) signal specification. However, it must be stressed that
this capability is only to be used for test purposes and not
intended for operational use. Note that SPS and PPS users will
not be affected.
For information concerning: BLOCK II see file . . . . . GPSB2
GPS SYSTEM see file . . . . . GPSSY
TIME TRANSFER see file . . . . . GPSTT
--
File GPSTD
last updated
Wed Sep 28 12:06:44 UTC 2005
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Relevant Pages
- GPS CONSTELLATION STATUS -- Fri Sep 9 12:22:15 UTC 2005
... Scheduled Coordinated Universal Time (UTC) Time Step ... GPS will not be adjusted physically. ... Change to GPS Broadcast Navigation Message On June 2, 1995 beginning approximately 1900 UT, the GPS Master Control Station began adding data to the spare data fields in the broadcast navigation message. ...
(sci.geo.satellite-nav) - Re: Extra leap seconds due to earthquake?
... > internationally-agreed extra leap second or seconds that are sometimes ... > On the GPS front, I think that GPS internal system time (UTC as at ... > satellites) is now 13 seconds ahead of today's UTC, ... It is expected that Celestial Pole offsets related to the IAU1980 Nutation ...
(sci.geo.satellite-nav) - Re: Lep seconds
... Have come across requirements in MIL sat comms systems that need GPS time as ... well as UTC. ... TAI or even GPS. ... never signals leaps, NTP will deliver TAI. ...
(comp.protocols.time.ntp) - Re: GPS-UTC Leap Corrections
... GPS (as opposed to UTC) internally, so we want the computers on the ... The time servers speak NTP ...
(comp.protocols.time.ntp) - Re: Extra leap seconds due to earthquake?
... >> On the GPS front, I think that GPS internal system time (UTC as at ... >> satellites) is now 13 seconds ahead of today's UTC, ... any news on when the next leap second will be added? ... > It is expected that Celestial Pole offsets related to the IAU1980 Nutation ...
(sci.geo.satellite-nav) |
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