RINEX Files for LEO Satellites
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                          Werner Gurtner

                          April 13, 2000


Basically the RINEX definition contains enough fields to accommodate most of
what we need for a LEO. There is no difference between an airborne kinematic
application or an earth-bound rover and a LEO. The ANTENNA: DELTA H/E/N
values don't have any meaning here. Maybe, but I haven't thought it to the
end, one could interpret the H/E/N components as orbit-fixed coordinates of
the antenna relative to the center of mass of the spacecraft or rover
(H=Radial up, N=along track to the front, E=cross-track to the right).

All other header values are still meaningful, with the exception of course
of the approximate coordinates.

In the RINEX standards the ANTENNA: DELTA H/E/N and APPROX POSITION XYZ
header records are not optional, i.e., we should include them with zero
values, but I am not sure that one should be so strict here.

There is an event flag (2) to show that the data has been collected in kinematic
mode. I think it should be included as first record in the data part.

Using the event flag 4 we can switch to a higher data rate (e.g., during
the profiling) without violating the rules.

I have generated a fictitious sample file to show these features:


     2.10           OBSERVATION DATA    GPS                 RINEX VERSION / TYPE
XXRINEX  V9.9       X AGENCY            13-APR-00 14:43     PGM / RUN BY / DATE
EXAMPLE OF A LEO FILE                                       COMMENT
Y SAT                                                       MARKER NAME
AUTO                Z AGENCY                                OBSERVER / AGENCY   
    11              GPS U               1.2.3               REC # / TYPE / VERS 
    22              ANT V                                   ANT # / TYPE
     1     1                                                WAVELENGTH FACT L1/2
     4    L1    L2    P1    P2                              # / TYPES OF OBSERV 
    30.000                                                  INTERVAL
  2000     2    23     0     0    0.000000                  TIME OF FIRST OBS   
  2000     2    23    23    59   30.000000                  TIME OF LAST  OBS   
                                                            END OF HEADER       
 00  2 23  0  0  0.0000000  2  1
                  *** KINEMATIC DATA ***                    COMMENT
 00  2 23  0  0  0.0000000  0  5 04 27 02 24 10                                 
 102296141.24300  79711270.47200  19466308.49900  19466306.44500                
 113059421.19300  88098244.13900  21514492.59500  21514490.94300                
 109345638.66600  85204387.98100  20807783.18700  20807781.67100                
 101864136.65600  79374648.77500  19384100.72400  19384099.96700                
 118437621.32400  92289049.10000  22537929.92200  22537928.29300                
 00  2 23  0  0 30.0000000  0  6 04 07 27 02 24 10                              
 102155655.84700  79601801.34400  19439575.04100  19439573.18200                
 150229330.99000  34666468.86700  28587691.09500   8465905.67400                
 113319889.39600  88301206.35600  21564058.07600  21564056.38500                
 109132580.73600  85038368.82100  20767239.55100  20767238.30900                
 101967907.29400  79455508.99200  19403847.71000  19403846.83200                
 118740301.61500  92524903.83500  22595528.06100  22595526.65500                
 00  2 23  0  0 31.0000000  4  2
     1.000                                                  INTERVAL
                  *** FROM NOW ON 1-SECOND DATA ***         COMMENT
 00  2 23  0  0 31.0000000  0  6 04 07 27 02 24 10                              

etc

Other (optional) header records like # OF SATELLITES or PRN / # OF OBS or
RCV CLOCK OFFS APPL etc are no problem either and can easily be included.