A method for estimating characteristics of signals received by a millimeter wave car radar is proposed. In this method, characteristics of the car radar hardware are taken into account. Moreover, a phenomenon that only a part of the target is irradiated with the radio wave from the radar antenna with a sharp beam is considered; the phenomenon is peculiar to the car radar which operates in a compact range. For the consideration of the phenomenon, a radar target is substituted with a set of scattering points. The positions of these scattering points and the RCS values for the scattering points are appropriately determined on the basis of an RCS image for the target; the RCS image means a spatial distribution of RCS values on the surface of the target. The RCS image is measured accurately by using the novel measurement method introduced in this paper.

Furthermore, the estimated characteristics of the signal received by the car radar are compared with the measured ones in typical cases of car radar environments. The comparison verifies that the received signal characteristics are well estimated even in the compact range. The proposed method has proved to be valid for the estimation of the received signal characteristics.
�@