Rinex Nav Broadcast Ephemeris File

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The RinexNavFile object provides the capability to read and write Broadcast Ephemeris data to and from a Rinex Navigation file. This is an ASCII file of GPS Broadcast Ephemeris data conforming to the RINEX standard.

 

RinexNavFiles (also known as GPS Broadcast Ephemerides) contain position, velocity, and clock information for all the satellites of the GPS constellation. FreeFlyer has the ability to read and write RinexNavFiles, but does not generate Broadcast Ephemeris data when propagating spacecraft. The time system is GPS Time, and positions and velocities are in the ECEF reference frame, which FreeFlyer converts into the MJ2000 frame.

 

Note: Due to its discontinuous nature, Broadcast Ephemeris data should not be used to propagate Spacecraft objects used for event detection. Instead, the Broadcast Ephemeris should be used to set the initial state of the Spacecraft and then an integration-based propagator, such as an RK89 or Cowell integrator, should be used to propagate it.

 

More information on the RINEX format can be found in several locations. Two example references are provided below:

 

http://en.wikipedia.org/wiki/RINEX

http://igscb.jpl.nasa.gov/components/formats.html

 

Additionally, historical RinexNavFiles and pre-processing utilities can be downloaded from multiple sources; four examples are provided below:

 

ftp://garner.ucsd.edu/pub/rinex/

ftp://cddis.gsfc.nasa.gov/gps/products/

ftp://data-out.unavco.org/pub/rinex/nav/

http://facility.unavco.org/software/preprocessing/preprocessing.html

 

An example of the format of a RINEX Nav file is given below.

 

    2              NAVIGATION DATA                         RINEX VERSION / TYPE

comb_nav.pl         SOPAC      Sat Aug  2 03:00:09 UTC 2008 PGM / RUN BY / DATE

                BROADCAST EPHEMERIS FILE                   COMMENT            

    SCIGN - Southern California Integrated GPS Network     COMMENT

                                                           COMMENT

     SOPAC - Scripps Orbit and Permanent Array Center      COMMENT

   IGPP - Institute of Geophysics and Planetary Physics    COMMENT

        SIO - Scripps Institution of Oceanography          COMMENT

       UCSD - University of California, San Diego          COMMENT

                                                           COMMENT

               email: archive@josh.ucsd.edu                COMMENT

                   ftp://garner.ucsd.edu                   COMMENT

                  http://sopac.ucsd.edu                    COMMENT

                                                           COMMENT

                                                           END OF HEADER      

2 08  8  1  0  0  0.0 1.981128007174D-04-2.728484105319D-12 0.000000000000D+00

   6.600000000000D+01-1.362500000000D+01 5.521301412937D-09 2.257403702520D+00

  -5.625188350677D-07 8.749986649491D-03 4.982575774193D-06 5.153745389938D+03

   4.320000000000D+05 1.080334186554D-07-1.301406564647D+00 1.695007085800D-07

   9.425145279018D-01 2.740312500000D+02 2.618450595652D+00-8.381063390645D-09

  -4.857345185067D-10 0.000000000000D+00 1.490000000000D+03 0.000000000000D+00

   2.800000000000D+00 0.000000000000D+00-1.722946763039D-08 6.600000000000D+01

   4.319400000000D+05 4.000000000000D+00

2 08  8  1  2  0  0.0 1.980932429433D-04-2.728484105319D-12 0.000000000000D+00

   7.500000000000D+01-1.896875000000D+01 5.449155550630D-09-2.975670304909D+00

  -8.996576070786D-07 8.749276399612D-03 5.079433321953D-06 5.153746816635D+03

   4.392000000000D+05-9.685754776001D-08-1.301467271359D+00 1.210719347000D-07

   9.425119341481D-01 2.727812500000D+02 2.618483343073D+00-8.269273019842D-09

  -3.546576300567D-10 1.000000000000D+00 1.490000000000D+03 0.000000000000D+00

   2.800000000000D+00 0.000000000000D+00-1.722946763039D-08 7.500000000000D+01

   4.391400000000D+05

 

 

See Also


RinexNavFile Properties and Methods