卫星激光辅助光学影像立体测绘评估与分析

Evaluation and analysis of satellite laser assisted optical image stereo mapping

卫星激光辅助光学影像进行立体测绘是提高无控制测图精度的重要手段。针对美国ICEsat-1和我国高分七号、资源三号03星在轨激光测高载荷,本文从激光辅助光学影像提升高程精度的需求出发,采用激光与立体影像平高分离的区域网平差方法,对比和分析三颗卫星激光用于复合测绘的精度。试验选取天津同一地区的资源三号03星传感器校正立体影像和三颗卫星激光数据,利用15个外业检查点进行精度验证。试验结果显示,利用6~10个ICEsat-1、高分七号、资源三号03星激光点辅助光学立体影像平差后,立体影像定位高程精度分别由原始的4.64 m提升到2.51 m、2.4 m、3.48 m,充分表明,三颗卫星激光数据均可用于进一步提高立体影像高程精度,GF-7卫星激光辅助定位高程精度效果略优于ICEsat-1,ZY3-03星次之。

Satellite laser-assisted optical imagery for stereo mapping is an important tool to improve the accuracy of uncontrolled mapping.Aiming at the on-orbit laser height measurement load of ICEsat-1 and GF-7 and ZY 3-03,the paper starts from the demand of laser assisted optical image to improve the elevation accuracy, and adopts the block adjustment method of level and height separation for laser and stereo image, compares and analyzes the accuracy of three satellite lasers for composite surveying and mapping.In the experiment, the stereo image of ZY3-03 satellite sensor in the same area of Tianjin and the lasers of three satellites are selected, and 15 RTK points are used for accuracy verification.The experimental results show that after using 6~10 laser points of ICEsat-1,GF-7 and ZY3-03 to assist optical stereo image adjustment, the stereo image positioning accuracy increased from the original 4.64 m to 2.51 m, 2.4 m and 3.48 m respectively.It is fully demonstrated that the laser data of all three satellites can be used to further improve the elevation accuracy of stereo images, and the effect of laser assisted positioning elevation accuracy of GF-7 satellite is slightly better than that of ICEsat-1,followed by ZY 3-03.