[IGSMAIL-4502]: Substantial loss of GLONASS tracking

[Stefan Schaer]

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IGS Electronic Mail      16 Jul 06:54:12 PDT 2003      Message Number 4502
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Author: Stefan Schaer 
 
 
Dear colleagues, 
 
A sudden GLONASS tracking interruption was reported (and actually 
solved) concerning 2 IGLOS stations, OS0G (Onsala, Sweden) and IRKJ 
(Irkutsk, Russia): 
 
  http://igscb.jpl.nasa.gov/mail/iglosmail/2003/msg00080.html 
  http://igscb.jpl.nasa.gov/mail/iglosmail/2003/msg00081.html 
  http://igscb.jpl.nasa.gov/mail/iglosmail/2003/msg00082.html 
 
We could observe a similar problem (temporary or even permanent loss of 
GLONASS tracking) for many other IGLOS stations: 
 
  BOGI* 
  CAGZ 
  CONZ 
  HUEG 
  LEIJ 
  MTBG* 
  SPT0 
  SUNM* 
  TITZ 
  UNB1 
  WTZZ 
  YARR* 
 
Those stations indicated with "*" are still non-GLONASS tracking  
stations. The number of members joining the "club of GPS-only IGLOS 
stations" increased from 3 (LHAZ, REUN, REYZ) to 7. GLONASS tracking  
data is becoming scarce, and consequently GLONASS (precise) orbit  
determination more and more difficult ... 
   
The most striking GNSS tracking problems are listed below: 
 
BOGI* JPS EUROCARD      GLONASS data missing as of D188/189 
CAGZ  JPS EUROCARD      GLONASS data missing from D190 through D193 
CONZ  JPS LEGACY        GLONASS data missing on D191/192 
DARR  JPS LEGACY        GLONASS data incomplete on D188; 
                        no GNSS observation data available as of D190 
DAVR  ASHTECH Z18       GLONASS data incomplete on D194 
GODZ  ASHTECH Z18       Low GNSS data volume 
GOPE  ASHTECH Z18       GLONASS data incomplete as of D190 
HUEG  JPS LEGACY        GLONASS data missing on D188/189 
IRKJ  JPS LEGACY        GLONASS data missing from D188 through D190 
JOZE+ TRIMBLE 4000SSE   G21 not tracked as of D185 
KR0G  ASHTECH Z18       G02 not tracked 
LEIJ  JPS LEGACY        GLONASS data missing on D189/190 
LHAS+ AOA SNR-8000 ACT  G27 not tracked  
LHAZ* ASHTECH Z18       No GLONASS tracking 
MDVJ  JPS LEGACY        Probably inactive receiver; 
                        no GNSS observation data available as of D184 
MTBG* JPS LEGACY        GLONASS data missing as of D189 
NOVJ  JPS LEGACY        Some GPS satellites not tracked 
OHI3  ASHTECH Z18       Some GLONASS satellites not tracked 
REUN* ASHTECH Z18       No GLONASS tracking; 
                        G05 not tracked 
REYZ* ASHTECH Z18       No GLONASS tracking; 
                        G08 not tracked 
SPT0  JPS LEGACY        GLONASS data missing on D190/191 
SSIA+ TRIMBLE 4000SSI   G01 not tracked 
SUNM* JPS LEGACY        GLONASS data missing as of D189/190; 
                        low GPS data volume 
THU2  ASTECH Z18        G02, G03 not tracked 
TITZ  JPS LEGACY        GLONASS data missing on D190 
UNB1  TPS LEGACY        GLONASS data missing on D188/191 
WROC  ASHTECH Z18       R22 not tracked 
WTZZ  ASHTECH Z18       GLONASS data missing from D188 through D190 
YARR* ASHTECH           GLONASS data missing as of D190 
 
"+" indicates non-IGLOS IGS receivers. 
 
 
Best regards, 
 
Stefan