I want to post-process GPS files via Differential processing (DGPS/DGNSS mode)

using rtklib (http://www.rtklib.com/).

I have rover and base observations in .rinex format.

I took FINAL satellite orbit solutions from NOAA-CDDIS archive (https://cddis.nasa.gov/Data_and_Derived_Products/GNSS/orbit_products.html) in the following format:


Using the utility rtkpost from rtklib I get the error "no nav data".

Is that a problem of the sp3 format? (sp3 is listed within the acceptable formats)

Did I download completely wrong files for the satellite orbit solutions?


2 Answers 2


This is a known issue:

RINEX NAV is always needed even with precise ephemeris and clocks. It's used to recognize unhealthy satellites.



The "no nav data" comes from rtkpost not having an idea where your base station is. Check out the Options/Positions/Base Station settings and make sure it is set to use include the RINEX nav file, the Obs file Header, or an explicit position as desired.

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