Geosynchronous spaceborne–airborne bistatic synthetic aperture radar (GEO-SA-BiSAR) can achieve high-resolution Earth observation with superior system flexibility and efficiency, which offers huge potential for advanced SAR applications. In this article, the echo characteristics of GEO-SA-BiSAR are analyzed in detail, including range history, the Doppler parameters, and spatial variance. The distinct features of GEO-SAR and airborne receiver result in the failure of the traditional bistatic SAR range model and imaging methods. In order to deal with these problems and achieve high-precision data focusing on GEO-SA-BiSAR, this article first proposes a novel range model based on one-stationary equivalence (RMOSE) to accommodate the distinctiveness of the GEO-SA-BiSAR echo, which changes with orbit positions of GEO transmitter. Then, a 2-D frequency-domain imaging algorithm is put forward based on RMOSE, which solves the problem of the 2-D spatial variance of GEO-SA-BiSAR. Finally, simulations are presented to demonstrate the effectiveness of the proposed range model and algorithm.

中文翻译：

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使用基于单稳态等效的新型距离模型进行地球同步星载-机载双基地 SAR 数据聚焦

地球同步星载-机载双基地合成孔径雷达（GEO-SA-BiSAR）可以实现高分辨率对地观测，具有优越的系统灵活性和效率，为先进的SAR应用提供了巨大的潜力。本文详细分析了GEO-SA-BiSAR的回波特性，包括距离历史、多普勒参数和空间方差。GEO-SAR和机载接收机的鲜明特点导致传统双基地SAR距离模型和成像方法的失败。为了解决这些问题，实现聚焦GEO-SA-BiSAR的高精度数据，本文首先提出了一种基于单平稳等价（RMSE）的新型距离模型，以适应GEO-SA-BiSAR回波的独特性。 ，随着 GEO 发射机的轨道位置而变化。然后，提出了一种基于RMSE的二维频域成像算法，解决了GEO-SA-BiSAR二维空间方差问题。最后，通过仿真来证明所提出的距离模型和算法的有效性。