Objective Spaceborne lidar has a high orbit and wide observation range, which facilitates the accurate and rapid acquisition of largescale threedimensional spatial information. It is a key research area, both domestically and internationally. Spaceborne lidar has been increasingly used in marine remote sensing and topographic mapping. With the continuous development of China's space laser altimeter, the measurement accuracy has increased from 5.0 m to 0.3 m. The stability requirements of the opticalmechanical structure continue to increase and the measurement accuracy also increases at the same time. Simultaneously, the laser itself is also a highly sensitive component of the optomechanical instrument. There can be shape and position errors of the onboard interface owing to factors such as production, emission vibration, and changes in satellite temperature. These errors lead to a deviation in the optical axis of the laser altimeter. The traditional installation method considers the rigidity requirements of the instrument rather than the precision requirements. In this study, the core accuracy of the altimeter is considered to be the main optimization goal. The flexibility of the supporting structure is optimized to isolate a part of the deformation caused by the outside surroundings. This ensures that the optical accuracy of the laser altimeter is better than that of the traditional method.Methods This study designs the support structure of an altimeter based on the kinematic installation method. The rigidity of the optical plate of the laser altimeter is enhanced, and the rigidity of the supporting structure is reduced as much as possible while meeting the requirements of the satellite. Thus, most structural deformations caused by changes in the mechanical and thermal environments are isolated. The flexibility of the support structure is implemented by the arcuate hinge, and the parameters of the arcuate hinge are optimized to set reasonable flexibility. The structural deformation of the deck which is caused by the change in the
