中高轨卫星海洋成像图像几何定位精度提升方法

Method of Improving Accuracy of Image Geometric Positioning for Medium and High Orbit Satellite Ocean Imaging

针对中高轨卫星海洋成像时缺少控制点下的图像定位精度提升问题,提出一种提升定位精度的方法。该方法利用中高轨卫星成像范围大,配合姿态机动,在短时间内寻找有特征点的区域,通过卫星图像与高精度控制图像进行匹配,寻找控制点,求解偏置矩阵,并将该区域的偏置矩阵补偿到海洋地区,以达到提升图像定位精度的目的。结合中高轨卫星成像特点,对河南嵩山检校场和太原区域图像进行仿真,并利用嵩山检校场数据进行在轨几何检校,将检校参数补偿到太原区域。仿真结果表明:无控制点定位精度从118.3个像素提高到37.8个像素,证明了文章提出方法的有效性。

Aiming at higher accuracy of image geometric positioning for medium and high orbit satellites ocean imaging when lacking of GCPs(ground control points), a method is proposed to enhance the image geometric positioning accuracy. This method takes advantage of the large imaging range of the medium and high orbit satellites, so that the satellite can find areas which have feature points in a short time with the help of attitude maneuvering. Bias matrix can be obtained through high-precision matching between the satellite image and control image, and then the image geometric position accuracy in the ocean can be improved by compensating the bias matrix to the targeted zone. Combined with the characteristics of medium and high orbit satellite imaging, the image of Henan-Songshan calibration field and Taiyuan are used for simulation. The data of Songshan calibration field after geometric calibration is used to compensate the image of Taiyuan. The simulation results show that the positioning accuracy without GCPs is improved from 118.3 pixels to 37.8 pixels proving the validity of the method proposed.