In RINEX observation file header, there is a line with APPROX POSITION XYZ label. Value of this line is approximate marker position in geocentric coordinate-system (unit: meter). Following Example shows a RINEX OBS File header. How much is the standard deviation of These values?

     3.02           OBSERVATION DATA    M (MIXED)           RINEX VERSION / TYPE
TPP 3.10.4                              20180325 235959 UTC PGM / RUN BY / DATE          
CKSV                                                        MARKER NAME                       
 -2956619.1390  5075902.2771  2476625.5647                  APPROX POSITION XYZ 
  • 1
    I don't feel secure enough to make this an answer, but this thread from RPLSToday states that it could be very accurate or could be bogus, so you can't trust those values without checking them or trusting the provider based on previous checks.
    – mkennedy
    Commented May 25, 2018 at 20:48

1 Answer 1


The answer is (simply) unknown.

The present day GNSS Receivers are (definitely) much more advanced compared to their predecessors in terms of computing power, algorithms (in firmware), antenna design, and etc. And the modern day Receivers definitely know the variance-covariances. But maybe because the RINEX specifications do not make it mandatory or optional, these values are not output.

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