I sort of doubt if you need to get into spherical geometry. Here are some questions to help answer that question for sure:

1. What is the maximum distance from you to any one of the ten stationary objects? In other words, how far does the telemtry work? If you are only talking about short distances, then you can probably approximate the earth's surface as a plane.


2. How precisely do you know your position and that of the stationary objects? Unless you know them very precisely, any errors resulting from the assumption of a flat plane will be small compared to the uncertainty of the positions themselves.

As for whether an 8-bitter can do this task, that depends mostly on how often you need to update your estimate of the closest object. I don't think you have mentioned that requirement yet. As Christoph mentioned, it really would help if you could give a complete description of the problem.

-- Russ