高分七号卫星立体影像无地面控制区域网平差与精度验证

Block Adjustment Without GCPs and Accuracy Verification for GF-7 Satellite Stereo Images

开展基于高分七号卫星(GF-7)立体影像的无控区域网平差精度分析验证,对GF-7能否实现1∶1万比例尺立体测图具有重要意义。文章选取了覆盖中国河北太行山地区的GF-7立体影像和激光点作为实验数据,开展无地面实测控制点条件下的区域网平差实验。结果表明,在无激光点辅助的情况下,实验影像在各类地形及整区的平面精度均满足1∶1万比例尺测图要求,但高程精度超限。采用激光点作为控制与立体影像开展联合区域网平差后,实验影像平面和高程精度均满足1∶1万比例尺测图要求。因此,在无地面实测控制条件下,利用GF-7激光点作为高程控制,GF-7影像几何精度可满足1∶1万比例尺立体测图精度要求,这对未来开展全球范围1∶1万比例尺地理信息资源建设具有重要意义。

The accuracy analysis and verification of block adjustment without ground control points(GCPs)based on GF-7 stereo image is of great significance to whether GF-7 satellite can achieve 1∶10000 scale stereo mapping.In this study,GF-7 stereo images and ground laser altimetry points(LAPs)covering the Taihang mountains in Hebei province of China are selected as the test data to carry out block adjustment test without GCPs.The results show that without LAPs,the plane accuracy of the test image in all kinds of terrain and the whole area meets the accuracy requirements of 1∶10000 scale mapping,but the elevation accuracy exceeds the limit.After the combined block adjustment is carried out with LAPs control and stereo image,the plane and elevation accuracy of the test image meet the accuracy requirements of 1∶10000 scale mapping.Therefore,under the condition of without GCPs,using GF-7 LAPs as elevation control,the geometric accuracy of GF-7 image can meet the requirements of 1∶10000 scale stereoscopic mapping,which is of great significance for the future.