Yeah, some shows did have their own consistent-ish systems, but I think some shows used a system that seemed to be relative to the center of the solar system, others from the perspective of the ship (which makes more sense to me, like naval bearings) - https://memory-alpha.fandom.com/wiki/Heading.
It was a quick lookup from a long time ago, I was working on a 3d space game and was curious if ST had a consistent model I could just use.