Passive bistatic inverse synthetic aperture radar imaging and cross-range scaling of maneuvering target based on a noise-resistant parameters estimation algorithm

For passive bistatic inverse synthetic aperture radar (PB-ISAR) imaging of maneuvering targets, the complex motion of the target causes non-uniform time-varying bistatic angle and non-uniform rotation of the target, which leads to the severe bistatic distortion and defocusing in the generated ISAR image. To obtain a focused, well-scaled PB-ISAR image that can show the accurate shape and size of the target, the essential issues, including bistatic distortion, image defocus, and range and cross-range scaling (RCRS), must be addressed. An innovative PB-ISAR imaging and cross-range scaling method is proposed for obtaining ISAR image of the maneuvering targets under low SNR condition. First, we estimate the multi-dimensional parameters to approximate the non-uniform time-varying bistatic angle and non-uniform rotation of the target. Then, based on the estimated parameters, the bistatic distortion correction, defocus terms elimination, and RCRS can be performed subsequently. Finally, a focused and well-scaled PB-ISAR image of the target can be obtained. The proposed method can work under a low signal-to-noise ratio. The simulation results validate the effectiveness of the proposed method.