An empirical sea clutter model for low grazing angles

Abstract

The most fundamental characteristic of sea clutter, as used in radar performance evaluation, is its apparent reflectivity defined as σ° (m2/m2). The word apparent is used here as a reminder that any measurement of sea clutter reflectivity inevitably includes the effects of propagation close to the sea surface. Sea clutter reflectivity depends on many factors including sea state, wind velocity, grazing angle, polarization, and radar frequency. A comprehensive tabulation of measurements from around 60 sources were included in the 1991 edition of Nathanson's book [1] and this probably represents the most complete database of sea clutter reflectivity available. Also included in this book by Nathanson was a detailed description of an empirical sea clutter model proposed by Horst et. al. [2], the so-called Georgia Technical Institute (GTI) model. This model has found widespread acceptance in the radar community although its technical basis may be somewhat vague.