Geolocation is one of the key synthetic aperture radar (SAR) image processing procedures in SAR-based remote-sensing applications. The conventional SAR imagery geolocation model is based on the range-Doppler (RD) equation, which is derived from the Fresnel approximation of SAR. Currently, there is no other rigorous geolocation model for modern high-resolution SAR; however, this approximation may not be fully applicable for various modern SAR imaging modes and algorithms. This study aims to develop a novel SAR image geolocation model based on the SAR range history (RH) equation, which is derived from the basic SAR backscattered signal property. Moreover, a new geometric calibration model is presented for RH-based locations. Experiments based on real spaceborne SAR data are presented as examples, and the location accuracy of RH and RD location models are compared. The results show that the location accuracies of the RH and RD models are consistent under the existing SAR processing framework, but those for the RH model demonstrate better performance in the azimuth direction. In theory, the proposed RH model can be used for SAR image products generated from complex modes and non-Fresnel-approximation-based imaging algorithms, making it suitable for future SAR systems.

中文翻译：

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通过范围历史记录合成孔径雷达图像的位置


地理定位是基于 SAR 的遥感应用中关键的合成孔径雷达 (SAR) 图像处理程序之一。传统的 SAR 图像地理定位模型基于距离-多普勒 (RD) 方程，该方程源自 SAR 的菲涅尔近似。目前，现代高分辨率SAR还没有其他严格的地理定位模型；然而，这种近似可能并不完全适用于各种现代SAR成像模式和算法。本研究旨在开发一种基于 SAR 距离历史 (RH) 方程的新型 SAR 图像地理定位模型，该方程源自 SAR 后向散射信号的基本特性。此外，还为基于 RH 的位置提出了一种新的几何校准模型。以基于真实星载SAR数据的实验为例，比较了RH和RD定位模型的定位精度。结果表明，在现有SAR处理框架下，RH和RD模型的定位精度是一致的，但RH模型在方位角方向上表现出更好的性能。理论上，所提出的RH模型可用于由复杂模式和基于非菲涅尔近似的成像算法生成的SAR图像产品，使其适用于未来的SAR系统。