A motion compensation technique for stepped-frequency radar with phase slope analysis

When a stepped-frequency radar is used to obtain the synthesized high resolution range profiles (HRRPs) of high speed space objects, accurate motion compensation must be conducted, as object motion severely distorts the synthetic HRRPs. A novel method for estimating the motion parameters of a moving object from its stepped-frequency radar returns is presented. Motion parameters can be determined by analyzing the slope of the unwrapped phase function of the received radar signals. This method uses the maximum likelihood phase gradient estimation to calculate the phase slope of the radar signatures. Least squares estimation is incorporated into the phase slope analysis to reduce estimation errors. Numerical results show that the motion parameters can be accurately estimated and the HRRP distortion can be corrected.