Simultaneous imaging of multiple targets in an inverse synthetic aperture radar

A method for simultaneously obtaining the radar images of multiple targets is described. Before imaging, the orbital parameters of target are estimated by considering every complex target as a simple single-point target and performing motion compensation for each target. The maximum likelihood (ML) method is utilized to estimate the orbital parameters. An efficient algorithm for computing the ML estimator of the orbital parameters is presented. Simulation results on the imaging of two targets in rectilinear motion are given. In the case of ISAR (inverse synthetic aperture radar), a large number of pulses can be used to estimate the orbital parameters of only a few targets. The algorithm presented for computing the ML estimator of the orbital parameters is computationally efficient in this case