高分多模卫星图像定位精度保证设计与验证

Design and Verification of Image Positioning Accuracy Assurance for GFDM-1 Satellite

从高分多模卫星相机成像和处理链路出发,对图像定位精度的影响环节和因素进行研究,针对主要影响因素结合当前设计水平综合考虑,建立了包含轨道确定、姿态测量、时间同步、结构稳定性、相机内方位元素稳定性、地面标定与处理等多个方面的天地一体化图像定位精度保证体系,针对各项提出了具体的系统配置和软件算法设计方案,分别采取了仿真分析、测试和试验等方法进行了验证。介绍了高分多模卫星在轨的轨道确定,姿态测量,内、外方位元素稳定性的情况,对下传的图像几何定位精度进行分析和评价,实际在轨表现与设计预估状态基本一致,表明图像定位精度设计方案和控制措施有效,实现在星下点30°角范围内图像无控制点定位精度优于5 m(1σ)。

Regarding to the camera imaging and processing chains of GFDM-1 satellite,the influence aspects and factors of image positioning accuracy are studied.Based on the main factors combined with the current design level,a system of space-ground integration image positioning accuracy indicators is set up including orbit determination,attitude measurement,time synchronization,structural stability,camera intrinsic parameters stability,ground calibration and processing etc.Each design scheme with system configuration and software algorithm is verified by methods such as simulation analysis,measurement and testing.The application of GFDM-1 satellite on-orbit orbit determination,attitude measurement,and stability of internal and external orientation elements are introduced.The geometric positioning accuracy of images transmission is analyzed and evaluated,and the actual on-orbit performance is basically consistent with the estimated state of the design,indicating that the design scheme and control measures of image positioning accuracy are effective.The image positioning accuracy without ground control point is less than 5m(1σ)within the view angle range of 30°.