Detection Probabilities for Log-Normally Distributed Signals

摘要

The amplitude and power of a large family of radio signals are observed to have log-normal probability density functions. Among these are signals propagated through random inhomogeneous media, a notable example being low frequency atmospheric radio noise. Of greater importance are certain radar targets that have been observed to have essentially log-normal density functions. Both ships and space vehicles may fall into this category. Curves of probability of detection versus signal-to-noise ratio for the case of log-normal signals in Gaussian noise have been computed and are presented. The curves apply for square-law detection with varying degrees of post-detection linear integration. Both slowly and rapidly fluctuating signals are considered. It is shown that for log-normal signal distributions having large variances the probability of detection differs significantly from that obtained using curves based on an assumed Rayleigh signal distribution. (Author)