A Two-Step Sequential Procedure for Improving the Cumulative Probability of Detection in Radars

摘要

This Memorandum discusses a simple two-step search procedure for phased-array radars. The two-step procedure consists of illuminating each beam position in turn with a single transmitted pulse, and testing for the presence of a return signal from a target in each of m range positions. If the preset threshold is crossed in any range cell, a second higher-energy pulse (or train of pulses) is transmitted, a test is again performed on the return waveform, and a second threshold is used for comparison. If the second threshold crossing is observed in the same range cell, the decision is made that a target is present at that range. If the first threshold is not crossed, or if the first is crossed but the second is not, the decision is made that no target is present, and the next beam position is examined. Such a method is easily implemented in a phased-array radar, where the transmitting beam may be made to stop instantaneously (or return) when necessary to transmit the confirmation pulse. (Author)