Positioning Accuracy Optimization And Reliability Improvement Of Surveying Satellite

On the base of the deep analysis of surveying satellite imaging model and sensor calibration method, positioning accuracy optimization and reliability improvement technology of stero imaging satellite are researched deeply. The main achievements and innovations are summarized as following:1. According to the imaging mechanism and characteristic of high resolution surveying satellite, rigorous geometric models and positioning accuracy optimization methods of typical surveying satellite sensors are researched through induction and analysis. The results can provide a basis for the research of positioning accuracy optimization and reliability improvement technology for the following surveying satellites.2. After analyzing the rules of satellite orbit and attitude, a simplified exterior model is established which is suitable for the surveying satellite sensor. According to physical factor, the addition parameter model which is used for geometric calibration is constructed. Multiple types of geometric calibration way and ground control point distribution program are constructed. Under conditions of different exterior orientation models, addition parameter models and ground control point distributions, a set of experiments are made using ZY03 panchromatic camera and ALOS PRISM datas in different geometric calibration ways. Some valuable and significant conclusions are attained according to the changes of the geometric calibration parameters of satellite sensors in different areas and different time.3. Block adjustment models used to improve positioning accuracy which are based on rigorous geometric model and rational function model are constructed. According to the characteristic of satellite photogrammetry, a self-calibration block math model which is suitable for surveying satellite is constructed with orbit and attitude datas. The orbit constraint and distribution of ground control points are researched. With few ground control points, the block adjustment precision is good with one trip and multipled trips of satellite images.4、To solved the problem of iteration diverge and positioning accuracy optimizing without ground control point, a block adjustment methond which is based on based images is established. This methond can get a good inner block adjustment precision using one trip and multipled trips of satellite images and provide a basis for the high precision processing of the next level of surveying products. To improved the position precision without ground control point, the SRTM datas and commercial satellites which have a high poisition precision are used in block adjustment.5、The basis reliability theory is analyzed for improving the reliability of satellite position. A few methonds of detection of gross errs are achieved. After analyzing the results of detection of gross errs, the parameter values of weight function are adjusted and an self-adaption methond of detection of gross errs is established. The results show that the self-adaption methond has a good effectiveness.