A method of determining the point source quality of a set of pixels associated with a detected energy signature is discussed that pre-records ideal test point source signatures at various sub-pixel locations and radiant intensities throughout the overall sensor field of view in a focal plane array, determines the sub-pixel location of an observed source, and compares the signature at a pixel of the observed source to the pre-recorded “ideal source” signatures at the determined sub-pixel location. to determine point source correlation.