Target course recognition using nonsinusoidal look-down radars

The target signature of an airplane as viewed by a nonsinusoidal look-down radar is obtained analytically as a function of target shape, azimuth orientation, look-down angle, and transmitted pulse duration. The information contained in the target signature can be used for detection of stationary and moving targets in heavy clutter, as well as the recognition of target shape and orientation. The relation between target signature and target azimuth orientation shows that pulse lengths shorter than airplane length are required to perform target recognition at all azimuth angles. Target course recognition in the radar ground plane is the process of determining the azimuth angle by selecting from the database the target signature that is most similar to the observed one. The effect of look-down angle on the target signature is also analyzed. At small look-down angles, target shape information is obtained with pulse lengths shorter than aircraft length. However, at large look-down angles pulse lengths much shorter than the airplane length are required. The variation of the target signature with azimuth and look-down angles are utilized for determining two-dimensional target course recognition. Cruise missile radars operating in a lookdown mode can utilize the very-high-resolution nonsinusoidal radar to enhance target shape recognition in addition to target course recognition