资源三号卫星传感器校正产品定位精度验证与分析

Accuracy Analysis and Validation of ZY-3's Sensor Corrected Products

在已有对资源三号(ZY-3)卫星遥感影像质量初步验证工作的基础上,选择同时具有平地和山地的典型实验区影像,进一步深入研究并验证ZY-3卫星传感器校正产品的定位精度。以在实验区外业测量的高精度GPS点作为控制点及检查点,通过区域网平差算法对传感器校正产品自带的有理多项式系数进行精化,消除系统误差;通过自动生成数字表面模型(DSM)和正射影像(DOM),验证其平面测图和立体定位精度,分析地形、控制点数量与分布对精度的影响。实验结果表明:在地形平坦地区,ZY-3卫星数据的平面定位精度可达1.476 m,高程定位精度可达2.213 m;在地形起伏较大的山区,平面定位精度可达1.506 m,高程定位精度可达2.895 m。该精度能满足1∶5万比例尺DEM及DOM制作要求,并可用于1∶2.5万比例尺地形图的修测。

On the basis of the existing preliminary accuracy validations of ZY-3 satellite imagery,a further in-depth analysis and verification of the geopositioning accuracy were performed at a typical site with both flat and mountainous terrains.The rational polynomial coefficients（RPC） were refined through block adjustment with high accuracy GPS points as ground control points（GCP） and check points.Digital surface model（DSM） and digital ortho map（DOM） were automatically generated with the refined RPC,the planimetric and stereo geopositioning accuracies were evaluated,and the influences of terrain,number and distribution of GCPs were analyzed.The results show that the horizontal and vertical geopositioning accuracies of ZY-3 imagery of the test site are 1.476 m and 2.213 m respectively in the flat area,and 1.506 m and 2.895 m respectively in the mountainous area,all meeting the requirements of 1∶ 50 000 DEM and DOM production both in the flat area and mountainous area.The ZY-3 imagery can also be used for revision of the 1∶ 25 000 topographic maps.