willhartley:
I thought about this for a moment actually. I was like huh, i could just do that but then I would lose the ability to log on the rocket too when I inevitably lose signal 60k+ feet.
There is no compelling reason I can see to 'parse' the data coming from the GPS at all, its already in CSV format, so post processing with a spreadsheet after the event should be easy enough.
As for needing to log in the rocket as well, attach an openlog to the GPS, the TX from the GPS can easily feed the HC12 and openlog at the same time.
Openlogs are cheap too, £4 ish.
I dont know the line of sight range of the HC12, but I guess you might be getting close at 20-30km. Easy solution to that is to put a decent low noise amplifier in front of the ground based HC12, that should provide around 12dB of signal gain in a typical FSK device such as the HC12 and that represents a range increase of 4 times.