Study On The Techniques Of High Precision Georeferencing For Optical Satellite Imagery

This dissertation makes a comprehensive analysis and study on the subjects related to high-precision of optical satellite imagery, which includes the models of exterior orientation parameters, in-flight calibration of photogrammetry parameters, bundle adjustment supported by the ephemeris and attitude auxiliary data, etc. Based on this, the dissertation aims to establish a complete theoretical system and technical method for processing optical satellite imagery. The main achievements and innovations are summarized as following:1. According to the characteristics of linear array CCD sensors, kinds of coordinates related to the satellite imaging geometry model have been introduced in detail, the rigorous imaging geometry model of satellite has been established, combined with the auxiliary data of satellite, several imaging geometry models have been constructed.2. In view of the obvious systematic error existed in ephemeris and attitude auxiliary data, and which often leads the poor direct positioning accuracy. Based on this, the calibration models of attitude systematic error have been built, and the experiment results indicate that this method can improve the direct positioning accuracy effectively.3. The models of exterior orientation parameters have been established in order to describe the characteristics of linear array sensor’s position information and attitude information. Through the pre-process of rotation and transformation in imaging geometry models, the attitude auxiliary data can be changed into exterior orientation angular parameters, which lays the theoretical foundation for calibrating the internal parameters and the bundle adjustment.4. The in-flight geometric calibration model of photogrammetry parameters has been established, a method of calibrating internal parameters is proposed, which describes the internal parameters with constant model and polynomial model in piecewise. Meanwhile, the calibration model of external patameters has been established, kinds of factors affected the positioning accuracy are united to an orthogonal rotation matrix. Experiments and analysis have been done with different calibration methods and the results show the correctness and calidity of the calibration methods of photogrammetry parameters.5. Bundle adjustment model and self-calibration bundle adjustment model described by different models of exterior orientation parameters have been established, meanwhile, an in-depth study on the correlation issues between unknown parameters together with the solutions and weight tactics are made. Parameters of geometric calibration are introduced into the bundle adjustment model, the experiments indicate that results with calibration do much better than the results with auxiliary data directly, and this verifies the validity and necessity of geometric calibration algorithm proposed in this paper.6. A method of constructing Rational Function Model(RFM) is proposed, and the tie-points are generated through image matching with dependent terrain program. Based on the parameters of geometric calibration, the RFM has been constructed with different control programs and are used for direct georeferencing, the experiment results show that this method can improve the direct positioning accuracy of satellite imagery without ground control points significantly.