Antenna processing for surface target detection

An antenna processing system for target detection in receiver noise and heavy clutter is formulated by means of spacetime decision theory. The theory is applied to the case of a single target in clutter, with unknown target location and unknown amplitude and phase of the target return. The clutter background is assumed to be uniform in average power over the field of view. The target detection is accomplished by means of a generalized likelihood ratio test. A block diagram of the resulting decision-theoretic antenna processing system is shown. The decision-theoretic array does not form a beam in the ordinary sense, and consequently has equal gain in all directions in the forward hemisphere. However, the usual loss in gain occurring in conventional antennas which are omnidirectional does not occur in the decision-theoretic array. The decision-theoretic array is compared with conventional arrays to show the improvement possible by using the former. The quality criterion used to compare the systems is average risk, or the average probability of error in decision making. The array requires no scanning of any sort and is fixed relative to the vehicle that carries it.