Complex Natural Resonances of Radar Targets via Prony's Method.

摘要

It has been shown that extraction of complex natural resonances and residues from exact transient responses via Prony's method is both efficient and accurate. However, in the art of radar interrogation the exact transient response is difficult to obtain and the authors must be content with an approximate one. Knowing the complex natural resonances of objects is essential to one type of radar target discrimination. In this paper the authors consider the use of Prony's method in extracting complex natural resonances from approximate backscattered ramp responses of radar targets. A ramp waveform is used in radar target discrimination because a good approximation to the time domain response can be obtained with only a few harmonically related frequency domain responses via Fourier synthesis. By applying Prony's method to this approximate ramp response, a few dominant resonances which are close to the origin of the complex frequency plane can be extracted. This is quite encouraging because for the purpose of radar target discrimination only a few dominant modes are needed. Objects considered are prolate spheroids, simple wire aircraft models and some realistic aircraft models. The accuracy of this method is found to be good when compared to the results obtained by other techniques.