Key Technology Research of Satellite-Ground Intergrated Design on Optical Remote Sensing Satellite

With the advancement of satellite technology, satellite manufacturing has evolved from being merely functional to being efficient and user-friendly. Designing satellites from the perspective of satellite-ground integration is a sophisticated approach to achieve efficiency and usability. This article summarizes several key technologies that require integrated satellite-ground design, based on the development experience of multiple optical remote sensing satellites. Foremost, the core indicator of satellite-ground integrated design is the accuracy of uncontrolled positioning. By analyzing the error chain, it is necessary to strictly control the orbit measurement error, star sensor attitude determination error, time synchronization error, and camera optical axis determination error throughout the satellite manufacturing process to ensure that the final uncontrolled positioning accuracy meets the requirements. Additionally, this article proposes suggestions for improving uncontrolled positioning accuracy both on the satellite and on the ground. The second key aspect involves designing the on-orbit radiometric calibration mode based on satellite-ground integration. To improve the frequency and quality of radiometric calibration, the satellite should be designed with imaging modes such as 90-degree yaw calibration and moon-oriented calibration, and the ground should be equipped with corresponding processing algorithms to achieve efficient on-orbit radiometric calibration and improve image quality. The third aspect involves designing the on-orbit geometric calibration mode, including star-oriented calibration and 180-degree yaw calibration, to enhance the frequency and effectiveness of geometric calibration. The fourth aspect focuses on designing the data transmission link for satellites carrying multiple payloads, ensuring that data is transmitted effectively through dual channels. Often, space-ground transmission errors can cause the loss of frames on a certain channel. If the data of multiple payloads are randomly distributed across dual channels, the loss of frames on one channel could result in the inability to merge data from the two channels, leading to payload data loss. Therefore, in the data transmission design, arranging the data of the same payload within the same channel is recommended to avoid the distribution of the same payload's data across two channels. This approach enhances the robustness of the entire system by ensuring that any data loss on a specific channel only affects one payload, without impacting the data of other payloads. Finally, the design of auxiliary data for payloads is addressed. The auxiliary data must be complete and accurate, including the platform's GNSS positioning and orbit determination information, the attitude information from star sensors, the angular velocity information from the gyroscope, the imaging time for each row, and the parameters used during imaging.