Correction of Sampling Time Jitter for Stepped-Frequency Radar by Minimizing Entropy of Range Profile

There is a sampling time jitter in the stepped frequency radar system, which leads to phase discontinuities during the synthesis of a wideband spectrum, resulting in grating lobes of range profile. This paper derives the gradient of entropy with respect to the phase error coefficient by minimizing the entropy of the range profiles, and iteratively solves for the distribution of phase error in each sub-band. Subsequently, a linear regression method is used to more accurately estimate the error in each sub-band, and then to correct it. Finally, simulation results demonstrated the algorithm’s effectiveness by comparing the entropy of images before and after correction.