Evaluation And Optimization On Dynamic Imaging Quality Of An Optical Remote Sensor

The development of aerospace science provides a prospective future for the improvement of earth observation technology. As an important way, optical imaging remote sensing technology has been promoted rapidly. Its imaging quality has been further improved through following method: improving the quality of remote sensor itself, enlarging the focal length, and increasing the resolution of record medium and the transfer function of optical system; steadying the stability of spacecraft; enhancing the image motion compensation ability, etc. However, under space dynamic environment, the influence of spacecraft diversification and the vibration of optical remote sensor and each optical component on imaging quality can not be ignored. In this case, a method to evaluate the degradation of imaging quality caused by vibration is advanced in this paper. Meanwhile, in order to improve the imaging quality, several ways to decrease the influence are discussed. During the above analysis, following questions must be solved: correct analysis of the system excitation, accurate calculation of the system response with finite element method, effective method to evaluate imaging quality, and the optimization of dynamic imaging quality. All these questions are studied in theory successfully, the experimental verification is carried out satisfactorily, and the method has been used in practice. Including launch stage and in-orbit stage, the dynamic environment of the optical remote sensor is analyzed. In launch stage, to examine if the destroy and leftover deformation will create, the overall stiffness and strength of the optical remote sensor is analyzed. In order to prevent accidental damage during the launch environment test, a structural model is designed instead whose dynamic property is equivalent to the real one. It is helpful to reveal some relative rules before the coupling dynamic test is carried out. In in-orbit stage, there are many dynamic disturbance sources, include which attitude adjusting of the?spacecraft, manufacturing error and dynamic unbalance of the momentum wheel, attitude adjusting and low frequency vibration of solar array are analyzed in detail, and their III loading rule and acting. mode is confirmed. Furthermore, the response of the spacecraft and optical remote sensor is analyzed with finite element method. In the meantime, some necessary data to evaluate imaging quality are provided. Due to the dynamic disturbances, complicated spatial motion of the optical remote sensor and its components will be created, which will cause the image movement on focal plane during exposure. So the imaging quality will be degraded. In this paper, coordinate transformation method has been used to calculate the image motion and its compensation in an advanced optical imaging remote sensor successfully. Based on the combination of this method and coordinate transformation method in arbitrary spatial coordinates, we broaden its application. As a result, the image motion can be calculated with this method during exposure. Ray tracing method has demonstrated that the coordinate transformation method is correct. It is difficult to evaluate the imaging quality of optical system intuitively only through the image motion on the image plane. In order to evaluate the degradation of imaging quality caused by vibration effectively, we introduce the motion optical...