Radar spectroscopy

The eigenfrequency spectrum of a radar target constitutes a code which can be used for target identification purposes. It corresponds to poles of the scattering amplitude in the complex frequency plane which can be obtained from observed frequencies and decay constants of ringing resonances. These poles are obtained for spheres, spheroids, and finite-lengths cylinders using Waterman's code, and study the level shifts and splittings as a function of target shape. The use of the radar spectrum of a target for characterizing target shape is thus indicated.