Geocentric vs. Topocentric Objects

[Antonio-MIT]

Currently working to build an application that makes use of Skyfield, and I'm running into one primary error.

AttributeError: 'Geocentric' object has no attribute 'observe'

Please forgive the lack of detail, as I am unsure how to express this correctly - but I believe my question is this:
How do I ensure that my objects are using Topocentric coordinates; and is that what this error is suggesting the problem is?

[brandon-rhodes]

A topocentric location would have the same problem: both positions are moving, and so Skyfield doesn't know their motion relative to an inertial reference frame.

How are you generating the coordinate? If you're doing something like something.at(t), maybe you could grab an earth object from an ephemeris (see the docs), and try (earth + something).at(t). That way, the position will be measured not from the Earth's center, but from the Solar System barycenter.