Patent ID: 8829439

Claim:
A system for detecting targets comprising: at least one first receiver for receiving radiation emitted by a passing animal or human, the radiation received by the at least one first receiver comprising-beams of radiation spaced horizontally; at least one second receiver for receiving radiation emitted by a passing animal or human, the radiation received by the at least one second receiver comprising beams of radiation spaced horizontally and vertically such that the beams of radiation received by the at least one second receiver travel at different predetermined heights relative to the horizontal plane, wherein the radiation is received by each of the at least one first and second receivers through a Fresnel array having a plurality of channels; the Fresnel array of the at least one second receiver being inclined at an angle to the horizontal plane resulting in channels at different vertical and horizontal locations; and at least one processor for receiving data from the at least one first and second receivers, the at least one processor operating to locate a target passing in the vicinity of the at least one first and second receivers and approximating the height and width of a target based upon radiation entering the plurality of channels at differing vertical and horizontal locations; the height of the target being based upon the recordation of certain of the beams at a predetermined heights relative to the horizontal plane and the width of a target based upon the horizontal spacing of the beams.