GF-7 was successfully launched in Taiyuan in November 2019 and is the first sub-meter high-resolution stereo mapping satellite of China.The first domestic star map fusion star sensor is used on the satellite, with dynamic correction of the angle between the two star sensors, which can greatly improve the accuracy of satellite attitude determination.Based on the overall design of the GF-7 satellite,this paper studies the key geometric processing techniques in the processing of the GF-7 satellite to achieve high-precision positioning of the High Resolution 7 dual line array camera, and verifies the satellite’s geometric level through extensive verifications. Based on attitude measurement data and orbit measurement data, the GF-7 satellite has greatly improved its attitude and orbit determination accuracy by using star map fusion star sensors. And the GF-7 satellite has added a unified time system and a unified attitude orbit model, constructing a rigorous geometric model with multiple platforms and cameras.To address the issue of changes in payload pointing angle during the imaging process of the GF-7 satellite,it is not only necessary to accurately calibrate the geometric distortion curve of the on-orbit camera, but also to obtain the precise light pointing of each CCD imaging detector in the payload to create a high-precision standard image,providing precise internal orientation geometric elements for the production of high-precision standard image products to ensure the internal geometric accuracy of satellite image products.The accuracy of geometric positioning and stereographic mapping products of GF-7 satellite is verified by high precision basic data and field ground measurement points.The high-precision basic data uses the DOM image with a geometric accuracy of better than 1:2000 and the DEM data with a high accuracy of grid and earth accuracy better than 5 m, and the field ground measurement points use 71 ground control points evenly distributed on the image.The verification results show that the uncontrolled positioning accuracy of the camera can be controlled to about 6 meters.After introducing a few ground control points to carry out rigid translation, the plane geometric residual is about 1.4 m, and the elevation residual is about 0.86 meters, which meets the demand of high-precision stereoscopic mapping in China.Based on the practical experience of satellite data processing system construction, this paper mainly combines the load design features of GF-7 dual-array camera,studies the key technologies and methods of GF-7 satellite combined processing, so as to improve the research system in the field of high-resolution optical satellite image geometric processing.Finally, a large number of data are used to verify the accuracy, and the results show that compared with the previous satellites, the geometric calibration accuracy, geometric positioning accuracy and relative geometric accuracy of the front and rear cameras of GF-7 dual-linear array camera have been significantly improved., reaching the current foreign commercial satellite plane elevation geometric accuracy standards. This indicates that the domestic satellite high -precision satellite load platform and ground processing capacity rose to a new step,which is at the international advanced level and has important practical significance for the subsequent development of related satellite work.

GF-7 satellite;stereo mapping satellite;geometric check;Rigorous geometric model;attitude track data processing;star sensors;uncontrolled positioning accuracy;elevation residual;control points