TLE Target

[michaelbaisch]

Hello everyone,

I'm exploring the possibility of scheduling observations for satellites defined by their TLE. I've dug into Astroplan, but it seems there's no current functionality in that area. I did come across an older pull request that attempted an initial implementation of the "NonFixedTarget" object. It appears to be a generic approach where calculations for TLE targets could be facilitated through the coord_function argument. However, given the passage of time, I assume the integration with the rest of the code is likely outdated.

On the Astropy side, it seems that TLE coordinates aren't directly supported as a coordinate system, as outlined here. The recommendation appears to be to use another library, like Skyfield or SGP4, along with some custom code.

I'm curious to hear any thoughts on this matter. How could this be implemented? Are there more recent ideas related to the NonFixedTarget object?