Investigation on low-angle tracking technique for HRR radar

Accurate tracking of targets flying at low altitudes above a smooth surface is difficult because of the multipath propagation effects. In order to address this problem, a new method for eliminating the effects of specular components on the performance of radar low-angle tracking is presented. Using stepped frequency high range resolution (HRR) radar, one can obtain the target range profile from applying inverse fast Fourier transforms (IFFT) to the target echoes. By auto-correlation of target range profile, the path difference between the target and its specula can also be extracted, hence, the target altitude is estimated. The results of simulation and a range profile obtained from a stepped-frequency ultra-wideband trail radar (using 4GHz bandwidth) are also discussed