GLONASS: Mission Support
Jump to: Mission Support Status, Current Tracking Statistics, Mission Support Request
ILRS Mission Support Status:
SLR is used for precision orbit determination and also used to intercompare with microwave precision orbit determination. Since the early 1990's, satellite laser ranging data has been obtained on a total of more than 25 different GLONASS satellites. Currently, three of the GLONASS satellites (-87, -89, -95) are tracked in support of the IGLOS campaign.
The ILRS has supported the IGS IGLOS campaign since it's start in 1998 (then called IGEX-98). [ref: SLRMail 167]. The initial IGEX-98 campaign began on 19 October 1998 [ref: SLRMail 157], and was scheduled to end 19 January 1999, but a three months extension was granted until 19 April 1999 by the ILRS Governing Board (GB) [ref: SLRMail 216]. The IGEX-98 and corresponding ILRS GLONASS campaign extension were due to the 30 December 1998 launch of GLONASS-80, -81, and -82. GLONASS-80, -81, and -82 were added to this ILRS priority list on 22 February 1999 [ref: SLRMail 252]. SLR tracking of GLONASS-65 was discontinued due to problems on board the spacecraft. GLONASS-83, -84, -85 were launched on 13 October 2000.
On 21 April 1999, a two week extension was granted by the ILRS GB to provide time for the IGEX analyst centers to evaluate if the SLR portion of IGEX should be extended. On 15 May 1999, the GB approved the recommendation from the IGEX analysis centers to continue the ILRS support of IGEX indefinitely, but the number of requested GLONASS satellite supported has been reduced from nine to three (GLONASS-70, -72, and -79, ref: SLRMail 313). GLONASS-70 became non-operational and was replaced with GLONASS-80 on 20 October 1999. GLONASS-72 was replaced with GLONASS-78 on 29 June 2000, and tracking of GLONASS-79 ended around 14 August 2000 due to problems with the spacecraft. GLONASS-84 was added as a replacement for GLONASS-79 on 21 February 2001. In March 2003, GLONASS-86 tracking was terminated and tracking started on GLONASS-89 per request of the IGLOS Pilot Project.
The short-term goals of the IGEX/IGLOS campaign are [ref: SLRMail 119]:
- establish independent GLONASS orbits for the evaluation of orbits established with GLONASS-receivers
- establish GLONASS radiation pressure models
- establish and/or test combined SLR/microwave processing techniques
- establish GLONASS predictions for the Global SLR observation network
The long-term goals of IGEX/IGLOS campaign are:
- establish the role of SLR for calibration purposes of GPS and GLONASS
- research in the area "separation of gravitational and non-gravitational" effects for GLONASS and GPS using also Etalon observations
- possible stabilizing effect of SLR observations on GPS/GLONASS microwave-derived length of day (and integrated LoD=UT) and possibly nutation estimates.
- combined SLR/GPS/GLONASS analysis for these high-orbiting satellites
In fall 2005, the ILRS GB approved ILRS participation in the IVS CONT05 (CONTinuous tracking 05) campaign. There are unexplained differences of a few centimeters between the radio and SLR measurements being taken on both GPS and GLONASS. By participating in the campaign, the ILRS hopes that more intensive SLR tracking on these satellites will allow us to study and hopefully resolve the differences between the radio and optical systems.
A history of GLONASS tracking is given in the table below.
GLONASS Tracking Supporting IGEX-98 and through 2010
| Period | GLONASS Satellite Number | ||||||||||||||||||||||||||||
From |
To |
62 |
65 |
66 |
68 |
69 |
70 |
71 |
72 |
78 |
79 |
80 |
81 |
82 |
84 |
86 |
87 |
88 |
89 |
95 | 99 | 100 | 102 | 109 | 110 | 115 | 118 | 120 | 121 |
19-Oct-98 |
22-Dec-98 |
X |
X |
X |
X |
X |
X |
X |
X |
X |
|||||||||||||||||||
22-Dec-98 |
19-Feb-99 |
X |
X |
X |
X |
X |
X |
X |
X |
||||||||||||||||||||
19-Feb-99 |
15-May-99 |
X |
X |
X |
X |
X |
X |
||||||||||||||||||||||
15-May-99 |
03-Sep-99 |
X |
X |
X |
|||||||||||||||||||||||||
03-Sep-99 |
20-Oct-99 |
X |
X |
||||||||||||||||||||||||||
20-Oct-99 |
29-Jun-00 |
X |
X |
X |
|||||||||||||||||||||||||
29-Jun-00 |
25-Aug-00 |
X |
X |
X |
|||||||||||||||||||||||||
25-Aug-00 |
21-Feb-01 |
X |
X |
||||||||||||||||||||||||||
21-Feb-01 |
05-Feb-02 |
X |
X |
X |
|||||||||||||||||||||||||
05-Feb-02 |
20-Feb-02 |
X |
X |
X |
|||||||||||||||||||||||||
20-Feb-02 |
20-Mar-03 |
X |
X |
X |
|||||||||||||||||||||||||
20-Mar-03 |
26-Aug-05 |
X |
X |
X |
|||||||||||||||||||||||||
| 26-Aug-05 | 19-Apr-07 | X |
X |
X |
|||||||||||||||||||||||||
| 19-Apr-07 | 30-May-08 | X |
X | X | |||||||||||||||||||||||||
| 30-May-08 | 31-Mar-09 | X | X | X | |||||||||||||||||||||||||
| 31-Mar-09 | 08-Jul-09 | X | X | X | |||||||||||||||||||||||||
| 08-Jul-09 | 17-Feb-10 | X | X | X | X | ||||||||||||||||||||||||
| 17-Feb-10 | 06-Apr-10 | X | X | X | |||||||||||||||||||||||||
| 06-Apr-10 | 06-Sep-10 | X | X | X | |||||||||||||||||||||||||
| 06-Sep-10 | 31-Dec-2010 | X | X | X | X | X | X | ||||||||||||||||||||||
For additional information, read the IGEX write-up in the First ILRS Governing Board Meeting Minutes and the IGEX-98 Workshop Summary.
GLONASS Mission Support Request:
Not available.
