An ISAR Imaging Algorithm for Multiple Targets Based on Keystone Transformation

In the processing of radar echoes from m ultiple targets with different radial velocities, the conventional ISAR imaging algorithm is no longer valid. A Keystone transformation based imaging algorithm for multiple targets is proposed. By use of Keystone transformation at a proper reference time when the signal of each target can be separated in slant range, l inear range migration of all targets can be corrected simultaneously and it is e asy to separate the signals of one target from others in the range-doppler plan e. The higher order radial motion of each target signature is compensated separa tely using envelope correlation and PGA algorithms. The image of each target is obtained by applying a two-dimensional Fourier transform to its compensated sig nature. Computed simulation results show the efficiency of the algorithm.