1. Method for characterizing a ballistic item including the steps: a. Produce a sequence of digitized passive infrared images of the item at different focus points such that the deepest to the highest features are each in sharp focus in at least one image; b. tag each image with the ID of the item; c. tag each image with specifics of the imaging set-up including the focus position, and size of digitized image array; d. store the tagged image sequence in a database.