Another interesting possibility is to use GPS for a clock. [1] Apparently 1 microsecond accuracy. Maybe useful if you want to make the distance really far. Someone has an article [2] Would be cool if you could pool the resources of multiple amateur rigs over a great distance in ad hoc antenna arrays.
Yeah GPS is a good tool to sychronize over very long distances. Locally locked clocks might still be better for an array not far away from each other if done properly. GPS might be easier to implement for amateurs though.
Imagine every amateur radio astronomer pointing their dishes at the same thing. If they all upload their data with accurate enough GPS position & timing, it could probably be used.
We just need a standard file format that incorporates the thing being observed and some GPS time sync info (or other time sync source). Anything else? I'm game.