[IGSMAIL-4474]: CODE GNSS final orbits

[Stefan Schaer]

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IGS Electronic Mail      25 Jun 07:38:11 PDT 2003      Message Number 4474
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Author: Stefan Schaer 
 
 
Dear IGS/IGLOS colleagues, 
 
With reference to IGS/IGLOS Mail 4371/736 
 
  http://igscb.jpl.nasa.gov/mail/igsmail/2003/msg00149.html  
  http://igscb.jpl.nasa.gov/mail/iglosmail/2003/msg00036.html    
 
we are proud to announce that the CODE Analysis Center started  
production of GNSS, or GPS/GLONASS-combined final orbits commencing  
June 8, 2003 (GPS week 1222). The following CODE final products are  
affected by the satellite system expansion: 
 
- Orbits: Our SP3-c files now include satellite positions for the GPS  
  as well as the GLONASS constellation. The positions are generally  
  referred to IGS00 (and the GPS time frame). 
 
- SINEX: Our weekly SINEX contributions now include station coordinates 
  for a significant number of GPS/GLONASS tracking stations. GNSS-based 
  ERP parameters (and geocenter coordinates) are the consequence of the 
  common GNSS analysis.  
 
- Troposphere SINEX: Troposphere zenith path delay estimates are in 
  addition available for a significant number of GPS/GLONASS tracking  
  stations.  
 
- Clock RINEX: Not affected. Clock RINEX results are still a GPS-only  
  product. Precise GLONASS satellite clock offset values are not yet  
  computed. 
 
The CODE GNSS final products are accessible at 
 
  ftp://cddisa.gsfc.nasa.gov/pub/gps/products/1222/ 
 
or directly at 
 
  ftp://ftp.unibe.ch/aiub/CODE/2003/ 
  http://www.aiub.unibe.ch/download/CODE/2003/ 
 
IMPORTANT NOTE: The test phase concerning GLONASS orbit determination  
at CODE is completed. Long-arc and especially SLR validation indicates 
an orbit quality on the 1-decimeter level, namely for both CODE final  
and rapid GLONASS orbit products. 
 
 
Status concerning the current GNSS satellite constellation: 
----------------------------------------------------------- 
 
- 28 active GPS     satellites (G22 inactive as of D148)  
-  9 active GLONASS satellites (R07 inactive as of D130) 
 
Remarks:  
  G22 is not yet officially decommissioned from service.  
  It is not really clear why R07 is off. 
  R08 was again declared "usable" in the course of D174.  
 
 
Status concerning the IGLOS stations considered at CODE: 
-------------------------------------------------------- 
 
  cagz (C ): ok 
  conz (  ): ok 
  crar (CF): just included, not yet official IGLOS station 
  darr (A ): ok 
  davr (AF): ok 
  dwh1 (  ): ok 
  godz (AF): currently excluded due to low GNSS data volume 
  gope (  ): ok 
  hert (C ): ok 
  irkj (CF): ok 
  khaj (  ): ok 
  kr0g (C ): ok 
  lhaz (CF): excluded, no GLONASS data, receiver replacement planned 
  mat1 (CF): ok 
  mdvj (  ): sudden data problem, receiver in repair 
  mtka (  ): ok 
  novj (  ): ok 
  ohi3 (C ): ok 
  reyz (C ): excluded, no GLONASS data, receiver replacement planned 
  sunm (  ): currently excluded due to low GPS data volume 
  thu2 (A ): ok 
  unb1 (  ): ok 
  yarr (CF): ok 
  zimj (C ): ok 
 
Legend:  
  "A" denotes an antenna-sharing receiver,  
  "C" an IGLOS site co-located with an IGS site, and  
  "F" indicates those sites where the corresponding IGS site is  
      addressed as IGS00 fiducial site. 
 
Remarks:  
  "ok" does not necessarily mean complete GNSS tracking data.  
  "AF" sites are already used for datum definition.  
 
 
Last but not least, let us point out that all IGS/IGLOS RINEX  
observation files with a latency exceeding 65 hours (!) cannot be  
considered in our final GNSS analysis: 
 
  http://www.aiub.unibe.ch/download/igsdata/glonass_final.txt 
  http://www.aiub.unibe.ch/download/igsdata/iglos_final.txt 
 
Data availability chart with all IGS/IGLOS sites used at CODE: 
 
  http://www.aiub.unibe.ch/ionosphere/codnet_30_late.txt 
 
The total number of available GNSS sites in our rapid analysis shows  
still pronounced variations (with minima on weekends ...): 
 
  http://www.aiub.unibe.ch/download/igsdata/glonass_rapid.txt 
  http://www.aiub.unibe.ch/download/igsdata/iglos_rapid.txt 
 
Please send us a short message if you notice a discrepancy with respect 
to a particular site. 
 
To avoid IGLOS data flow problems, approximately one third of the IGLOS 
observation data is downloaded directly from local ftp servers. 
 
Many thanks to the IGLOS station managers for their cooperation. 
 
Best regards, 
 
Stefan