NearbySearchStrategy

A search strategy is a provider of search areas. The Nearby Search Strategy is to be used when roughly know:

1. Where the telescope is pointing
2. What our field of view is

This is generally the case when plate solving with an aligned telescope. The alignment might be a bit off, and therefore coordinates off a bit. In these cases the assumption is pretty close, and not many solves are required to figure out what the telescope is actually pointed at.

The nearby behavior is simple, obviously the first area to search is the assumed correct coordinate with the given field of view. If that doesn't appear to be correct, we generate search areas around the given coordinate with the same field of view, until the threshold distance from our assumed center coordinate is reached, ordered by distance from the assumed center.

So three parameters are required:

1. The assumed center coordinate
2. Image field radius
3. Search area radius

The generated search areas would be something like this (green marks the center, red marks the generated search areas around it):