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Positioning Application: Why does the GLONASS UDD file not include all the parameters specified in the RINEX file?

  • PosApp V4.03 SR01 onward with the use of  'Rinex_Parser.exe' (see FAQ14528 for more information)
  • Rinex V2.10 only
  • The tk parameter is not required because PosApp auto populates the navigation message with the tk value based on the scenario start time and time into run
  • The tb parameter and P1 Flag are not required as PosApp does this automatically. Explanation and example below:-
    • Start a scenario at 00:00 hours (in the scenario tree) with an update interval of 30 mins (as specified in the UDD header)
    • The tb value will be 195 minutes (because GLONASS time is 3 hours, 180mins, ahead of UTC and an additional 15mins is needed because the tb value is reported half way through the 30 minute update interval).
    • The tb value will remain at 195 minutes until the next update interval.
    • The P1 flag is determined by PosApp based on the interval update rate given in the UDD file header (30mins in this example) and consecutive values of tb.
  • The P2 Flag changes based on the value of the tb parameter and therefore is not required in the UDD file as PosApp calculates these
  • The P3 Flag is automatically populated in the nav data because PosApp is always aware of the number of satellites for which almanac data is transmitted within the given frame
  • The P4 flag is based on the UDD header update rate and time into run. Both of which PosApp calculates

Product : SimGEN,PosApp,GLONASS