There is a dedicated playlist for the GPS videos dating back to 2016. So 32 videos in about six years. So you might have a little time to catch up. While the first video is pretty introductory as you might expect, by the time you get to video 7 the topics switch to things like the C/A code, BPSK, and gory details of all the frame data, including the IODC word.
We aren’t sure what he’s going to do in the other 68 videos, but it is sure to be interesting if you want to know all about GPS. If you don’t, you might still enjoy some of his playlists on calculus, physics, or other interesting topics. The ones we watched were all very informative.