RTKLIB StuffRTKLIB is a free and open source toolset for working with GNSS data. Using specialized receivers designed for surveying and geodisy and adding correction information available via the internet, it's possible to obtain position locations with an accuracy of a centimeter or less. These tools can also provide very accurate time and frequency comparisons of a local reference against the GNSS standard, and that's mainly why I'm interested in this activity.
RTKLIB is a well-established program with somewhat sporadic maintenance and development. The most recent version is 2.4.3 beta 31, which has been out for a couple of years. The main RTKLIB development is aimed at Windows, but it has been ported to Linux using the QT graphical toolkit.
Unfortunately, the version available in the Debian universe is the even older 2.4.3 beta 8, which lacks some of the features I need for timing. So, I decided to merge the various versions and add a few tweaks of my own to create a set of Debian packages for the current version 2.4.3b31. The results are in this "debs" directory, with builds for both amd64 and armhf (Raspberry Pi). The source code is in this "build" directory.
sudo pkg --install <full_deb_package_name>
NOTE 1: I have only half a clue about how to build and manage Debian packages. These probably don't conform to the standards but they should install OK with this command:
NOTE 2: The Raspberry Pi build ("*_armhf.deb" packages) hasn't been much tested, and a first run with rtknavi_qt shows some console errors and a propensity to crash on unexpected input. I suspect the command line versions, which is what you ought to be using on an RPi anyway, are more robust.