Removal of obscured surfaces ina a computer model

This report describes how spheres can be used to represent ships and decoys, such as flares and chaff clouds, as extended targets in simulations. The report also describes a detailed method for calculating how much, of each of the sphere used in the simulation scenario, is obscured by other spheres. The described method gives a better representation of extended targets than point sources as well as better (more realistic) outcome of the simulations involving IR or radar seeking missiles, ships and decoys.