Distribution losses for Weibull and lognormal clutter types

The calculation of the clutter-limited sensitivity of a surveillance radar relies on the power probability distribution of the clutter. With Weibull and lognormal clutter types, the power distributions take on a number forms via parameter settings relating to the prevailing environmental conditions. In order to maintain a constant rate of false target detections with a clutter background, the detection threshold must be adjusted to account for these particulars of the clutter distribution. The required change from a noise-based threshold to a clutter-based threshold may be expressed with the aid of a distribution loss for purposes of assessing the radar sensitivity. This paper provides a compact form for the distribution loss whenever the Weibull or lognormal distributions represent the clutter variation about the mean. While the form is an approximation, the efficiency it lends to sensitivity prediction may make it a desirable method of analysis.