Frequency-Modulated Continuous-Wave Synthetic Aperture Radar (FMCW SAR) is a promising compact remote imaging sensor. In this paper, a ground moving targets refocusing method is presented to provide FMCW SAR system with simultaneous moving targets indication application. This method is modified from range migration algorithm. To discriminate the target optimally, the concept of relative motion is utilized. The moving target is refocused like a fixed target. Its migrations both in the range and azimuth directions are completely compensated. Blind hypotheses of the relative velocities are used in the detection phase of moving targets. The step size between the hypotheses involves a trade-off between the computation load and detectability. In this paper, we determine the discretization based on the principle of stationary phase. The discretization reduces the computation burden and secures the detectability.
Frequency-Modulated Continuous-Wave Synthetic Aperture Radar (FMCW SAR) is a promising compact remote imaging sensor. Its detection and refocusing of the ground moving targets is discussed in this paper in order to provide FMCW SAR system with simultaneous moving targets indication application. A moving target indication method by focusing is derived and presented. This method is derived based on range migration algorithm taking into account the moving target range cell walk. To discriminate the target optimally, the concept of relative motion is extended to FMCW SAR. Due to continuous transmitting and receiving at all time, the standard “stop-go” approximation is not valid here. By searching the relative velocity, the moving target can be focused accurately, equivalent as a fixed target focused in squint mode. The maximum output corresponds to the best matched parameters. Thus the matched targets are detected and the others suppressed.