On determining the radar threshold from experimental data

To set the radar threshold for small false alarm probabilities, it is necessary to know the tail of the probability density function for the test statistic under the no target assumption. It is shown that the generalized Pareto distribution (GPD) can be used to approximate the extreme tail of the density function. As a result, fixing the threshold is equivalent to estimating the two parameters of the GPD. For a variety of probability density functions it is demonstrated that accurate results can be obtained with orders of magnitude fewer samples than are required by Monte Carlo simulation. The thresholds required for very low false alarm probabilities were obtained with a good deal of accuracy