Research On Key Technologies Of Orbit Design For Optical Remote Sensing Satellite

As an important data resource for earth observation, remote sensing satellite equipped with a variety of sensors can provide abundant information about the status and variation of earth surface. With the rapid development of space and information technology in recent years, space-borne remote sensing has entered a new stage of the massive sensors with high temporal resolution, spatial resolution or spectral resolution. But the remote sensing data still cannot satisfy the all demands in different applications, especially in the cases of emergency response, for the limitation of sensor performance, communication conditions, data distribution mode, and management system.The orbit is the most important factor to impact the data acquisition of RS satellite. This dissertation aims to improve the acquisition ability of remote sensing satellite by the optimization of its orbit. The key techniques of optimized orbit design were compared and analyzed, which includes satellite dynamics, design procedures, coverage performance metrics calculation, special orbit design and multi-objectives optimization algorithm. Some key problems of orbit design were solved in the research, which could support the optimized design of optical remote sensing satellite. The detailed contents were followings:1. The satellite orbital dynamics theory and remote sensing satellite orbit design procedures. The design procedures were introduced, the main aims of different steps were decomposed firstly; then, constraints and objectives of the design mode were presented.2. Special orbit design methods for optical remote sensing satellites. Optimization selection is the key step in the optical satellite orbit design. The dissertation focuses on special circular orbits, elliptical orbit design methods of optical remote sensing satellite. And a prototype system of wizard tools for optical remote sensing satellite orbit were developed based on the methods represented in this dissertation. 3. The key algorithm of coverage performance metrics for optical remote sensing satellite orbit. Coverage performance of the satellite orbit is regarded as an important objective in the orbit design. Imaging temporal windows forecast algorithm considering J2perturbation and the regional forecast algorithm for CCD imaging geometric model were proposed for the two key indicators, calculation of temporal resolution and the regional coverage rate.4. Orbit and constellation design method for optical satellite based on multi-objective optimization algorithm. Satellite orbit design is a typical multi-objective optimization problem(MOP), evolutionary algorithms is an effective tool to solve multi-objective optimization problem. NSGA-Ⅱ was selected as the optimization tool for single satellite orbit and constellation design.The main characteristics and innovation:1. Meeting local area coverage requirements with high temporal and spatial resolution, a critical repeat orbit elliptical orbit design method was introduced. The orbit has four major advantages:first, by placing the perigee over the hot spot areas, we can get the target’s image with very high spatial resolution; second, extends the interval of the regression coefficients, greatly reducing the orbital cycle of regression, a high time resolution can be realized; third, arched line has a good stationary characteristics due to the use of the critical orbit, to ensure that the same ground resolution for targets with the same latitude; fourth, it has a longer working life compared to circular orbit with the same attitude.2. Remote sensing satellite orbit and constellation design method based on multi-objective optimization algorithm (improved NSGA-Ⅱ algorithm) was proposed. According to the characteristics of the satellite orbit design tasks, we improved NSGA-Ⅱ algorithm, and optic remote sensing satellite orbit and constellation design method based on multi-objective optimization algorithm were proposed.3. Key algorithm of calculating optic remote sensing satellite covering performance metricswere put forward. Count two key indicators of the amount of orbit time resolution and the amount of coverage problem, we proposed two fast algorithms, one is taking into account the J2perturbation optical satellite imaging window forecast, the other is the linear CCD Satellite imaging area forecast algorithm based on geometric imaging mode. They are the useful tools to support the optimization of the design of the remote sensing satellite orbit.4. Based on the special orbit design method proposed in this paper, we have developed a wizard-orbit design of optical remote sensing prototype system (ODPSRSS) to improve the efficiency of the special orbit design.