一种机载SAR数据点目标辐射定标方法  

An Airborne SAR Data Point Target Radiation Calibration Method

作　　者：王崇阳 王亚超 温智磊 汪丙南 周良将 WANG Chongyang;WANG Yachao;WEN Zhilei;WANG Bingnan;ZHOU Liangjiang(Qilu Aerospace Information Research Institute,Jinan 250101,China;Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]齐鲁空天信息研究院,济南250101 [2]中国科学院空天信息创新研究院,北京100190

出　　处：《遥感信息》2023年第1期63-69,共7页Remote Sensing Information

摘　　要：针对机载平台姿态时变造成的天线波束指向不稳定而导致辐射精度下降的问题,提出了一种新的天线方向图定标方法。该方法基于sinc函数模型,考虑了飞机飞行过程中横滚角的影响,能够有效改善飞机姿态不稳导致辐射精度下降的问题。文章根据点目标响应能量计算、天线方向图定标和定标常数计算等关键步骤开展辐射定标研究,采用多波段机载SAR系统获取的C波段和X波段SAR数据对该方法的有效性进行了验证。积分法和峰值法的对比分析结果表明,结合本文新的天线方向图模型,积分法得到的相对和绝对辐射精度均优于峰值法,说明积分法提取点目标能量与本文改进的天线方向图模型结合的辐射定标方法能够满足高分辨率机载SAR数据辐射定标处理的要求。Aiming at the problem that the antenna beam pointing is unstable due to the time-varying attitude of the airborne platform,which leads to the decrease of radiation accuracy,a new antenna pattern calibration method is proposed.The influence of the roll angle can effectively improve the problem of the decrease in radiation accuracy caused by the unstable attitude of the aircraft.In this paper,the radiation calibration research is carried out according to the key steps of point target response energy calculation,antenna pattern calibration and calibration constant calculation.The effectiveness of the method is verified by the C-band and X-band SAR data obtained by the multi-band airborne SAR system.Through the comparative analysis of the integral method and the peak method,the results show that,combined with the new antenna pattern model in this paper,the relative and absolute radiation accuracy of the integral method is better than the peak method.It shows that the radiation calibration method combining the integration method to extract the point target energy and the improved antenna pattern model in this paper can meet the requirements of high-resolution airborne SAR data radiation calibration processing.

关 键 词：机载SAR数据 辐射定标 横滚角 天线方向图 点目标提取 

分 类 号：TP751[自动化与计算机技术—检测技术与自动化装置]