Design of a coherent inverse synthetic aperture radar moving target simulator

Generally, the time delay of simulated pulses generated by inverse synthetic aperture radar (ISAR) moving target simulator (MTS) is changing discretely with time. In this case, there must be time delay errors between simulated pulses and real pulses reflected by real target. As a result, the coherence of the simulated pulses will be worsened and the ISAR image would be blurred due to the time delay errors. In order to solve the problem, a compensating technique consisting of two steps is proposed. Firstly, if the simulated pulse and the real pulse are located at different range cells, move the simulated pulse into the range cells at which the real pulse are located. Secondly, compensate the phase errors between simulated pulse and real pulse. After step two, at the efficient sampling time instants, the digital samples corresponding to the simulated pulse are equal to that constructed from the real pulse. So the radar will treat the simulated target as a real target. In other words, the coherence and the ISAR image quality of the simulated target are guaranteed. The simulation results demonstrate the efficiency of the proposed technique.