Earlier quoted context omitted.
The satellite data persumably also needs to be purchased, the area is huge, and this island is relatively tiny.
I'm sure astronomy solves much harder "needle in a haystack" problems and we could probably use their methods
Aren't astronomy problems almost exactly the opposite?
In astronomy the background is mostly static, providing an excellent reference frame either when trying to discover/track a moving object, or when trying to overlap multiple images of the same object for better observations.
If you're looking for an unknown island your background is constantly changing, but you're looking for something which is somewhat static but might not actually exist.