Motion compensation for a frequency stepped radar

Abstract

A few hundred MHZ synthetic bandwidth requires the transmission of many (~100) frequency stepped pulses when a small instantaneous bandwidth (<10 MHz) is available. The actual trend in radar imaging is towards wide instantaneous bandwidth (>50 MHz) thanks to improved technology. However the need of retrofit of narrow instantaneous bandwidth to HRR (high range resolution) seems to be still cost effective in the industrial context. In this case the processing time, combined with a large synthetic bandwidth, requires a proper motion compensation of radial target velocity and acceleration. Target kinematics parameters are estimated by minimization of a like-autocorrelation cost function; this technique is capable of detecting minima of aliasing created by uncompensated motion condition. Accuracies are estimated by Monte Carlo simulation and compared to those achievable by entropy and contrast based techniques.