| 摘要: |
| 距离模糊比是星载SAR图像的一项重要指标，与正侧视成像相比，大斜视成像星地几何关系更为复杂，传统距离模糊计算与仿真中将地球视为球体的假设会对计算结果造成较大偏差，不能准确评估SAR图像质量。本文采用更为准确的地球椭球模型代替球体模型，并提出了一种基于斜视天线坐标系的模糊区计算方法，利用此方法对距离模糊比沿距离向测绘带的变化进行仿真，同时对距离模糊比沿方位向的空变性也进行研究。本文研究成果对星载SAR系统设计具有重要参考价值。 |
| 关键词: 大斜视星载SAR 距离模糊 椭球模型 |
| DOI：DOI:10.3969/j.issn.1672-2337.2024.04.010 |
| 分类号:TN958 |
| 基金项目:国家重点研发计划（No.2021YFC3000405） |
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| RASR of Nonzero Squint Spaceborne SAR Based on Ellipsoid Model |
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CAI Jiarui, LYU Jiyu
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1. Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China;2. School of Electronic, Electrical and Communication Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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| Abstract: |
| Range ambiguity signal ratio （RASR） is an important performance index of spaceborne SAR images. Compared with the zero squint SAR, the geometric relationship between the satellite and the earth in high squint SAR imaging is more complex. The assumption that the earth is regarded as a sphere in traditional RASR calculation and simulation will cause a large deviation in the calculation results, which will inaccurately estimate the SAR image quality. In this paper, a more accurate ellipsoid model of the earth is used to replace the sphere model, and an ambiguity region calculation method based on the squint antenna coordinate system is proposed. By using this method, the change of RASR along the range swath is simulated, and the spatial variability of RASR along the azimuth is also studied. The research results of this paper provide important reference value for the design of spaceborne SAR system. |
| Key words: high squint spaceborne SAR RASR ellipsoid model of the earth |
