非合作星载SAR图像定位技术研究

项目名称： 非合作星载SAR图像定位技术研究

项目编号： No.41301481

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 天文学、地球科学

项目作者： 赖涛

作者单位： 中国人民解放军信息工程大学

项目金额： 25万元

中文摘要： 非合作接收是指第三方接收卫星下发给合作方数据的手段。由于缺少密钥授权和格式说明，第三方难以从辅助数据中解译出成像几何参数。而传统合作星载SAR图像定位方法均需利用成像几何参数或控制点，因此不适应于非合作星载SAR参数欠缺情况。在研究星载SAR成像几何过程中，发现在卫星姿态固定条件下，目标多普勒参数具有随方位以及斜距有规律变化的特性。在准确估计多普勒参数基础上，利用该特性可反演出地面目标的距离和方位坐标，从而实现定位。其基本思路是：利用多普勒参数随方位和斜距变化特性，建立多普勒参数与成像几何参数的超定方程组，优化求解后实现距离精定位和方位粗定位。利用多普勒参数随轨道方位位置变化特性，建立基于卫星姿态的多普勒模型，综合运用曲面拟合和小波分解两种方法估计姿态误差并消除其对多普勒参数的影响,得到姿态固定的多普勒估计曲面；再与事先建立的同姿态下多普参考曲面匹配求得卫星轨道位置，实现方位精确定位。

中文关键词： 非合作星载SAR；图像定位；多普勒参数估计；曲面拟合；姿态估计

英文摘要： Non-cooperative receiving is that the third part receives the downlink data which is transmitted by satellite to cooperative receiving part. Lacking private key authorization and farmat explanation, the imaging geometrical parameters is difficult to be obtained from auxiliary data. Because the imaging geometrical parameters or location of the control point is needed in the conventional location methods of cooperative spaceborne SAR, the conventional methods cannot used in the imagery geo-referencing of Non-cooperative spaceborne SAR. The images without geo-referencing have few value in further application. The new imagery geo-referencing method for Non-cooperative spaceborne SAR is studied in this project. In the condition of stabilized attitude of satellite platform, the dopplor parameters are changed regularly with the orbit location of the satellite and the slant range. This characteristic is used in the imagery geo-referencing. Firstly, based on the characteristic of doppler paremeters changed with distance, overdetermined equation with doppler paremeters and imaging geometrical parameters are builded, and with this equation resovled, range location is obtained. Secondly, based on the characteristic of the doppler parameters changed regularly with the orbit location, utilizing doppler curve fitting estimates

英文关键词： non-cooperative spaceborne SAR；Image localization；Doppler parameters estimation；curved surfit；altitude estimation