Study On The Algorithm For Ground Position Based On Remote Sensing Image From Satellite Formation

In modern earth observation by satellite-based remote sensing, clusters of low-performance satellite flying in formation may provide enhanced performance over single high-performance satellite. This is especially true for photogrammetry and remote sensing based on the satellite formation where stereographic imaging may provide higher spatial resolution and temporal resolution. The high accuracy ground position based on remote sensing image from satellite formation had been being a hot topic of digital photogrammetry and remote sensing. This dissertation is to study on the algorithms for ground position based on remote sensing images from satellite formation. The results attained are as follows.The relative motion analysis and orbit design of satellite formation flying on circular orbits have investigated systematically. A new kinematics method based on zero inclination orbit transformation was proposed. The influence of the reference satellite inclination on surrounding satellite orbit has been analyzed by the new kinematics method. According to the rules of remote sensing satellite design, a satellite formation with high coverage performance and almost same orbital altitude has been designed, and the accuracy of the direct georeferencing based on remote sensing image has been analyzed.The relative orientation and attitude determination of satellite-borne camera is a key problem of ground position. The performance of two linear algorithm for relative orientation were compared, and the results show that the linear algorithm based on SVD of essential matrix was not suit for relative orientation of stereo images, and the affine factorization method is worked well for relative orientation of multiple images. The relative orientation parameters by factorization method can been refined by the bundle adjustment. An attitude determination algorithm base on the base line of satellite formation was proposed, which provides the necessary camera attitude information to the direct georeferencing. Two dynamic attitude estimation algorithms based on satellite dynamic model were studied. The simulation experiment results show that the accuracy of attitude determination depends on the accuracy of relative orientation, and the attitude accuracy of camera can be improved by nonlinear predicitive filter.To improve height accuracy of direct georeferencing, the combined block adjustment with relative control was studied, and the results were compared with the block adjustment with a few control points. The methods of coordinates transformation from satellite network to earth network and space projection for map were introduced.Image feature detection and subpixel location were basic task of photogrammetry and remote sensing. Through the survey of Image feature methods, a junction detection method based multi-feature was proposed. The junction subpixel location error caused by image noise, feature scale and feature attribute was researched, and the subpixel location error of road featurecaused by gray difference of two sides was analyzed.The technique of area-based image matching was researched from reliability, accuracy and efficiency. Based on the needs of reliability and accuracy, a fast optimal matching area selection method of matching feature was presented. To reduce the search space, a feature point matching algorithm base moment invariant and singular value decomposition was proposed, and a search strategy based on improved genetic algorithms was proposed to improve the efficiency of image matching. The results show that the reliability, accuracy and efficiency of matching area based on region are improved by those methods and search strategies.