A new method of cross-range scaling of low resolution radar

Ordinary low resolution radar can not distinguish the radar target in both range and azimuth. If we apply the technology of inverse synthetic aperture radar (ISAR) to resolve the difference among Doppler frequency of the scatterers on the target, we can obtain a fine resolution cross-range image. The cross-range scale depends on both radar wavelength and rotating angle of target relative to radar-line-of-sight (RLOS) during the coherent accumulation. The former is known while the latter is difficult to determine especially in the case of ISAR. But it is necessary to investigate the method of cross-range scaling of low-resolution radar, as it is very important to radar target classification and recognition. In this paper, a new approach is proposed which is based on the principle of interferometric inverse synthetic aperture. We calculate the phase difference of some scatterers between two instant cross-range images by two antennas, which are placed horizontally, adding the range between the two radar and the range of the target, and then absolute cross ranges of some dominant scatterers are obtained. We apply the proposed algorithm to the emulational data of two antennas. The processing results show that the proposed method is correct and effective.