Maximum likelihood motion compensation of a wideband linear FM radar waveform

A single scatterer maximum likelihood estimator (MLE) is examined for motion compensation of a wideband linear FM radar waveform. Although this is an over simplification of a real target scenario, it is reasonable because of the presence of dominant scatterers in radar targets. The MLE convergence properties are determined by examining the shape of the associated ambiguity over range, velocity and acceleration. In addition, the Cramer Rao bound is computed in closed form which shows that the velocity bound is decoupled from the corresponding bounds of range and acceleration. A fast MLE is then proposed which uses the Hough transform to initialize the MLE algorithm. Monte Carlo simulations show that the MLE attains the Cramer-Rao bound for low to moderate signal-to-noise ratio depending on the a priori estimates of range, velocity and acceleration.