If you want to explore deeper, there's some fun (and well commented) open source GPS processing codes in Octave/Matlab [1], coming from the excellent book [2].

If you want to explore deeper, there's some fun (and well commented) open source GPS processing codes in Octave/Matlab [1], coming from the excellent book [2]. Those are compatible with cheap RTL-SDRs. [3] also looks nice, but as I recall is Linux only. [1] https://github.com/kristianpaul/SoftGNSS https://github.com/kristianpaul/SoftGNSS [2] https://www.ocf.berkeley.edu/~marsy/resources/gnss/A%20Software-Defined%20GPS%20and%20Galileo%20Receiver.pdf https://www.ocf.berkeley.edu/~marsy/resources/gnss/A%20Softw... [3] https://gnss-sdr.org/ https://gnss-sdr.org/