Detection performance degradation due to signal uncertainties
Azizul H. Quazi, Albert H. Nuttall · The Journal of the Acoustical Society of America · 1988
Detection of a known signal in white noise using a matched filter depends on the signal-to-noise ratio (signal energy to noise spectral density). As the uncertainties of signal characteristics, such as phase and amplitude, increase, the required SNR must be increased in order to maintain the same detection performance. However, in both cases of known and unknown signals, it is usually tacitly assumed that the signal covers the total bandwidth of the detector and the total integration time. But, in real ocean environments, it is difficult to know the exact signal arrival time and the exact bandwidth required to cover the wide range of Doppler shifts. As a result, the actual detector may utilize a wider bandwidth, and the integration time may extend beyond the signal duration. This paper addresses the problem where the signal duration L is less than or equal to the actual integration time T, and the signal bandwidth B is equal to or less than the actual bandwidth W of the detector. The performance loss is shown as a function of TW/BL as it varies over a range of 1 to 1000, for various combinations of probability of detection and probability of false alarm. [Work supported by NUSC special initiative program.]