Modeling And Detecting Capability Analysis Of Space-based Space Object Optical Observation System

Space-based space object observation system is an important development direction in the future space situational awareness (SSA) area, and also an advanced technology in the current field of space exploration field. It has been of strategic significance for space missions and even for national security. In this thesis, based on the object geometric imaging, radiation and optoelectronics theories, a systematical study is given on the geometrical and physical models of space-based space object optical observation. And its detecting capability has been analyzed and an optimum design of the system has been carried out. The main work and innovations of the thesis are listed as follows.1. By analyzing the perspective characteristics of the space-based and ground-based observation approaches and comparing the optical and radar space-based observation methods, the feasibility of spatial objects observation through space-based optical approach is made clear. The developing status in this field is summarized and the necessity of investigating the space-based optical observation model and performance is pointed out.2. A geometric visibility model under multi-constraints is proposed for space-based spatial objects observation. Upon the geometric relation among orbital target, observation satellite, the earth, the sun, and the moon, an optical visibility determination model between the observation satellite and the orbital target is derived, and a visibility prediction method is given for the space-based optic observation. By the classical colinearity equations, a geometric imaging model is put forward for space-based space objects observation, which considers two-axis platform rotation parameters and represents the platform attitude in attitude Euler angles and quaternion.3. Utilizing the light scatting empirical models for materials with the incoherent and coherent features, a new light scattering model is derived for the complicated space object by means of integration on Effective Incident Section (EIS), which is expressed in the area of EIS and Average Reflectivity (AR). And a method capable of calculating the accurate EIS and AR by the computer graphic techniques is presented. An integrated model language considering the object's 3D shape, behaviors and optic feature is designed for the complicated space object. The simulation experimental result proves the effect of the model language and the correctness of the light scatting model.4. By the radiation transmission and the optoelectronics theory, a mathematical relationship is set up between the object reflection energy of the sun light and the number of photoelectron accepted by single CCD unit The modulation transfer functions (MTF) for each imaging step in the process of imaging are built by the linear filtering theory and imaging theory. And the influence upon imaging quality causing of both related motion and vibration of the satellite platform are analyzed.5. A detection sensitivity formula is derived for the space-based spatial object optical observation and quantitative analysis is made on the 1factors influencing the detection limited magnitude capability such as the optical system, CCD and exposure time. According to these influence factors, several methods which could improve the detection capability are given. To assist the design of the system, the influence law between the space-based sensor's coverage and the system's parameters such as orbit, sensor and observation time is also researched and analyzed.6. A small dynamic optical signal generator and imaging simulation system is designed and a dynamic display method for space objects is realized. Moreover, a detail explanation is given on the simulation method of stars background and space objects, the design idea of 3D engine for space objects rendering and the approach for imaging simulation of space object observation sensor. Finally, a set of experimental results is listed out.