The problem of characterizing the radar returns from complex man-made localized targets using airborne radar platforms has been and currently is a topic of tremendous interest. This paper presents results of modeling four generic types of ground targets, and analyzes the monostatic radar cross section (RCS) both in the frequency and the time domain. The recorded results reinforce the conclusion that in realistic situations return signals are complex enough to include higher order terms, other than the shifted in time and frequency replica of the transmitted signal. A mechanism is shown on how to estimate these higher order terms. The existence of these terms allows one to see how signals are structured in the time domain. This in turn may successfully lead in the development of suitable matched filters for the class of targets studied in this paper