S.R. Heister, N.G. Parhomenko, A.S. Heister

A synthetic-aperture radar (SAR) provides super-resolution of an object due to specific coherent processing of signals received during relative motion of radar and object. In case of inverse-synthetic-aperture radar (ISAR) object moves relative to motionless radar. ISAR that may be realized in radar is considered. The radar is intended for detecting automobile (object) and measuring object-s length. ISAR allows shaping azimuthal radiolocating portrait of an object that characterizes distribution of reflective properties of object. The radar may be used for solution of following tasks: Automobile type definition under dense traffic; Reliable detection of a traffic disturber due to simultaneous definition of automobile length and velocity. A depth of conception of spectral-temporal structure of reflected signal determines effectiveness of ISAR algorithms and accuracy of probing signal type choice. Mathematical model of temporal structure of signal reflected from moving ground object is considered. The model takes account of object height and radar phase center height. The model may be used for development of ISAR algorithms that provide maximal resolution. Approach to quality of ISAR resolution forecasting is developed on basis of spectral-temporal structure of reflected signal analysis. The approach is based on analysis of derivative of a phase changing law of reflected signals. The approach is also useful for optimization of geometric characteristics of radar-s disposition. Results of analysis of phase structure of signals reflected from moving object are represented. The analysis allows determining optimal range of angles of view that provides the best resolution.