点目标机载SAR辐射定标关键技术与方法  

Key techniques and methods for airborne SAR radiation calibration based on point target

作　　者：徐志达 程春泉[2] 杨书成[2] 谭建伟 XU Zhida;CHENG Chunquan;YANG Shucheng;TAN Jianwei(College of Geomatics,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;Chinese Academy of Surveying and Mapping,Beijing 100036,China)

机构地区：[1]山东科技大学测绘科学与工程学院,山东青岛266590 [2]中国测绘科学研究院,北京100036

出　　处：《测绘科学》2020年第5期72-78,共7页Science of Surveying and Mapping

基　　金：国家重点研发计划项目(2018YFF0215303);中国测绘科学研究院基本科研业务费项目(7771808)。

摘　　要：针对机载SAR影像的高精度辐射定标处理问题,该文分别利用积分法与峰值法计算点目标辐射响应能量、通过对SAR影像辐射特征分析及方法对比,采用sin c函数模型拟合校正天线方向图,结合雷达功率方程求解定标常数,进而建立了完整的点目标辐射定标方法和流程,并对关键技术中不同方法进行了比较分析。结果表明,积分法能量计算模型与sin c函数天线方向图校正模型结合的定标方法能够达到更高的相对和绝对定标精度,优化后的方法能够满足并高于高分辨率机载SAR应用对辐射定标精度的要求。Radiation calibration of airborne SAR images is the basis for realizing the quantitative processing of airborne SAR images. Radiation calibration based on point targets is a more general and convenient method. However,high precision is still the goal of improving the current point target SAR radiation calibration. For the key technology of high-precision radiation calibration processing for airborne SAR images,this paper uses the integral method and the peak method to calculate the point target radiation response energy,By analyzing the radiation characteristics of the SAR image and comparing the methods,the sinc function model is used to fit the corrected antenna pattern. Combined with the radar power equation to solve the calibration constant,the complete point target radiation calibration method and process are established,and the different methods in the key technology are compared and analyzed. The results show that the calibration method combined with the energy calculation model of the integral method and the sinc function antenna pattern correction model can achieve higher relative and absolute calibration accuracy. The optimized method can meet and exceed the requirements for radiometric calibration accuracy for high-resolution airborne SAR applications.

关 键 词：机载SAR 辐射定标 天线方向图 积分法 峰值法 

分 类 号：P237[天文地球—摄影测量与遥感]