SPACEWARN Bulletin Number 517


C. Spacecraft Particularly Suited for International Participation: Category I

Global Positioning System satellites useful for navigational purposes and geodetic studies. ("NNN" denotes no national name. SPACEWARN would appreciate suggestions to update this list. An asterisk [*] denotes changes in this issue.)

High precision (<20 cm) GPS constellation tracking data obtained from the network of about 80 dedicated global stations that are of interest to geodetic study may be obtained through the following services provided by the International Association of Geodesy (IGS)

     FTP:    igscb.jpl.nasa.gov  [directory /igscb]
     WWW:    http://igscb.jpl.nasa.gov/
     E-mail: igscb@cobra.jpl.nasa.gov

The standard format of the GPS information appeared in SPX-515. The following e-mail from Richard Langley may be more useful to the user community.

From:   SMTP%"lang@unb.ca"  7-OCT-1996 12:10:52.26
To:     SARDI
CC:
Subj:   Navstar GPS Constellation Status (96-10-07)

                        Navstar GPS Constellation Status
                                   (96-10-07)

Blk                      NORAD   Orbit   Launch
II       PRN  Internat. Catalog  Plane    Date
Seq  SVN Code    ID      Number  Pos'n    (UT)   Clock Available/Decommissioned
-------------------------------------------------------------------------------
Block I
      01  04  1978-020A  10684          78-02-22        78-03-29     85-07-17
      02  07  1978-047A  10893          78-05-13        78-07-14     81-07-16
      03  06  1978-093A  11054          78-10-06        78-11-13     92-05-18
      04  08  1978-112A  11141          78-12-10        79-01-08     89-10-14
      05  05  1980-011A  11690          80-02-09        80-02-27     83-11-28
      06  09  1980-032A  11783          80-04-26        80-05-16     91-03-06
      07                                81-12-18        Launch failure
      08  11  1983-072A  14189          83-07-14        83-08-10     93-05-04
      09  13  1984-059A  15039          84-06-13        84-07-19     94-06-20
      10  12  1984-097A  15271          84-09-08        84-10-03     95-11-18
      11  03  1985-093A  16129          85-10-09        85-10-30     94-04-13


Block II
II-1  14  14  1989-013A  19802    E-1   89-02-14   Cs   89-04-15 05:02 UT
II-2  13  02  1989-044A  20061    B-3   89-06-10   Cs   89-08-10 20:46 UT
II-3  16  16  1989-064A  20185    E-5   89-08-18   Cs   89-10-14 20:21 UT
II-4  19  19  1989-085A  20302    A-4   89-10-21   Rb   89-11-23 03:13 UT
II-5  17  17  1989-097A  20361    D-3   89-12-11   Cs   90-01-06 03:30 UT
II-6  18  18  1990-008A  20452    F-3   90-01-24   Cs   90-02-14 22:26 UT
II-7  20  20  1990-025A  20533          90-03-26        90-04-18     96-05-10
II-8  21  21  1990-068A  20724    E-2   90-08-02   Cs   90-08-22 15:00 UT
II-9  15  15  1990-088A  20830    D-2   90-10-01   Cs   90-10-15 00:39 UT

Block IIA
II-10 23  23  1990-103A  20959    E-4   90-11-26   Cs   90-12-10 23:45 UT
II-11 24  24  1991-047A  21552    D-1   91-07-04   Rb   91-08-30 04:44 UT
II-12 25  25  1992-009A  21890    A-2   92-02-23   Cs   92-03-24 11:00 UT
II-13 28  28  1992-019A  21930    C-5   92-04-10   Cs   92-04-25 20:32 UT
II-14 26  26  1992-039A  22014    F-2   92-07-07   Cs   92-07-23 19:43 UT
II-15 27  27  1992-058A  22108    A-3   92-09-09   Cs   92-09-30 20:08 UT
II-16 32  01  1992-079A  22231    F-1   92-11-22   Cs   92-12-11 14:49 UT
II-17 29  29  1992-089A  22275    F-4   92-12-18   Cs   93-01-05 16:39 UT
II-18 22  22  1993-007A  22446    B-1   93-02-03   Cs   93-04-04 05:20 UT
II-19 31  31  1993-017A  22581    C-3   93-03-30   Rb   93-04-13 20:53 UT
II-20 37  07  1993-032A  22657    C-4   93-05-13   Cs   93-06-12 16:15 UT
II-21 39  09  1993-042A  22700    A-1   93-06-26   Cs   93-07-20 12:54 UT
II-22 35  05  1993-054A  22779    B-4   93-08-30   Cs   93-09-28 19:29 UT
II-23 34  04  1993-068A  22877    D-4   93-10-26   Cs   93-11-22 18:20 UT
II-24 36  06  1994-016A  23027    C-1   94-03-10   Cs   94-03-28 14:20 UT
II-25 33  03  1996-019A  23833    C-2   96-03-28   Cs   96-04-09 21:17 UT
II-26 40  10  1996-041A  23953    E-3   96-07-16   Rb   96-08-15 15:05 UT
II-27 30  30  1996-056A  24320    B-2   96-09-12   Cs   96-10-01 15:28 UT

Notes
-----
1.  NORAD Catalog Number is also known as U.S. Space Command (USSPACECOM)
    object number.
2.  No orbital plane position = satellite no longer operational.
3.  Clock:  Rb = Rubidium; Cs = Cesium.
4.  Selective Availability (S/A) had been enabled on Block II satellites during
    part of 1990; S/A off between about 10 August 1990 and 1 July 1991 due to
    Gulf crisis; standard level re-implemented on 15 November 1991;
    occasionally off for test and other purposes.  Currently, PRN15 and PRN28
    appear to have little or no S/A imposed.
5.  Anti-spoofing (A-S) was activated on 94-01-31 at 00:00 UT on all Block II
    satellites (ref. NANU 050-94042); occasionally off for test and other
    purposes.  A-S was turned off on all satellites at 20:00 UT on 95-04-19 and
    back on on 95-05-10; off again between 95-06-19 and 95-07-10; and between
    95-10-10 and 95-10-31.  A-S has been off on PRN28 since 95-02-21.
6.  PRN number of SVN32 was changed from 32 to 01 on 93-01-28.
7.  The active clock on PRN01 was switched from a Rb to a Cs between 96-08-16
    and 96-08-22 (ref. USNO and NANUs 134-96229 and 141-96234).
8.  PRN05 and PRN06 are equipped with corner-cube reflectors for satellite
    laser ranging (SLR).  SLR tracking of the satellites will permit onboard
    clock errors and satellite ephemeris errors in GPS tracking to be
    differentiated.
9.  The decommissioning date for PRN06/SVN03 is the date of termination of
    operations of this satellite (ref. USNO) and is about 3 weeks later than
    other published dates for "deactivation".
10. PRN16 will be moved from the E-3 slot to the E-5 slot to make room for
    PRN10.  An orbit maneouvre was carried out on 96-08-19 (ref. NANUs
    120-96204, 137-96232).
11. PRN20 hs been unusable since 15:18 UT on 96-05-10 and will not return to
    service (ref. NANU 118-96204).  Cause of failure: loss of 3-axis
    stabilisation.  PRN20 was moved out of the B-2 slot to make room for PRN30
    (ref. NANU 162-96256).
12. PRN28 has been moved from the C-2 slot to the C-5 slot, about 40 degrees
    away.  This move, which was initiated on 96-03-06 by lowering the orbit of
    PRN28 by about 6 km, made way for PRN03.  PRN03 is a backup for PRN28 which
    has some undisclosed equipment problem.  PRN28 will remain on the air, with
    some subsystems shut down to conserve power (ref. NANUs 045-96066, NANU
    068-96100, and GPS World Newsletter).  The move was completed on 96-08-23
    (ref. NANUs 127-96236 and 144-96236).
13. PRN30 (SVN30) was launched on 96-09-12 at 08:49 UT.  It achieved initial
    usable status on 96-10-01 at 15:28 UT (ref. NANUs 162-96256 and 171-96275).
14. Announced date of next scheduled launch: 97-01-13 (first Block IIR
    satellite).
15. Compiled by Richard B. Langley, Dept. of Geodesy and Geomatics Engineering,
    University of New Brunswick.

===============================================================================
 Richard B. Langley                         Internet: LANG@UNB.CA or SE@UNB.CA
 Geodetic Research Laboratory               BITnet:   LANG@UNB or SE@UNB
 Dept. of Geodesy and Geomatics Engineering Phone:    (506) 453-5142
 University of New Brunswick                FAX:      (506) 453-4943
 Fredericton, N.B., Canada  E3B 5A3         Telex:    014-46202
Fredericton?  Where's that? See: http://degaulle.hil.unb.ca/NB/fredericton.html
===============================================================================

SPACEWARN Bulletin Number 517
SPACEWARN Bulletin Index

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Questions/comments about the content of these pages should be directed to:
The World Warning Agency for Satellites, wwas@nssdca.gsfc.nasa.gov
National Space Science Data Center, Mail Code 633
NASA Goddard Space Flight Center, Greenbelt, MD 20771

Page Curator:
Dr. Edwin V. Bell, II, ed.bell@gsfc.nasa.gov, +1-301-286-1187
NSSDC, Mail Code 633, NASA Goddard Space Flight Center, Greenbelt, MD 20771

NASA Official: J. H. King, joe.king@gsfc.nasa.gov
V1.0, 27 November 1996