[IGSMAIL-4530]: CODE ultra rapid GNSS orbits

[Stefan Schaer]

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IGS Electronic Mail      30 Jul 07:54:02 PDT 2003      Message Number 4530
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Author: Stefan Schaer 
 
Dear colleagues, 
 
Until recently, the CODE, or COU ultra rapid orbits/ERPs were directly 
derived from our rapid products. These results were actually pure 
predictions and were therefore treated in the IGU combination just for 
comparison purposes (although the previous IGU combined SP3 orbit files 
indicated COU as contributing analysis center).  
 
The current COU orbit/ERP products are now real (i.e., supported by 
hourly observation data). As a matter of fact, our ultra rapid products 
are GNSS products, since we do not only consider GPS but also  
GPS/GLONASS-mixed hourly observation data in our ultra rapid analysis.  
 
It should be mentioned that the IGLOS data volume with respect to 
hourly data is (still) very limited (DWH1, UNB1, plus many European 
stations). Anyway, the quality of COU GLONASS orbits is already  
significantly better than that of broadcast information. We hope that 
other IGLOS stations (in particular all remote IGLOS stations!) are  
encouraged to supply hourly observation data.  
 
Those of you interested in the quality assessment of COU GPS orbits 
are referred to the most recent igu-cmp-sum (comparison) files and  
future igu-sum (combination) files stored at  
 
  ftp://cddisa.gsfc.nasa.gov/pub/gps/products/ 
 
or made available by the IGS ACC at 
 
  ftp://ftp.gfz-potsdam.de/pub/pub/igsacc/product/ultra/ 
 
COU products should be considered for the first time in today's 15-UT 
IGU combination. 
 
Many thanks to Gerd Gendt for the adaptations in this regard. 
 
Best regards, 
 
Stefan