Research On The Algorithms Of High Precision Georeferencing For Space Linear Satellite Imagry

In recent years,the remote sensing image resolution enhances unceasingly with the rapid development of space technology,resulting in that they are widely applied in the economic and social development,also in our national defense construction,which demand for a higher positioning accuracy of remote sensing image.This dissertation commits itself to the research of the theory and practice of high-precision positioning of space linear satellite imagery,which includes the rigorous geometric imaging model,direct-positioning model optimization,in-flight geometric calibration.The main works of this paper are as follows:1.A method of fitting attitude data of TH-1 satellite is studied.Through the analyses of attitude and orbit data,a method of fitting attitude data with a combination of polynomials and sine function is studied to offset the impact of high-frequency and low-frequency error in attitude data.2.According to the imaging characteristics of space linear CCD sensors,a rigorous geometric model for TH-1 satellite and ZY-3 satellite is established,based on which direct orientation methods with single CCD or multiple CCD have been built.Experiments about direct orientation have verified the validity of rigorous geometric model in this paper.3.A simplified line-of-sight model without look angles is proposed.Firstly,in view of the obvious systematic error existed in attitude data of space linear satellite imagery,attitude systematic error correction methods base on euler angles and quaternion are established through the imaging characteristics.It also verifies the validity with experiments.Secondly,a stereo geopositioning method based on line-of-sight vector rectification is introduced,then a simplified line-of-sight model without look angles is proposed to overcome the defect that line-of-sight vector rectification model need the unknown ground point.It is proved to be feasible and correct,the whole positioning precision is better than attitude systematic error correction methods.4.An in-flight geometric calibration model with look-angle is designed.First,the in-flight geometric calibration model of photogrammetry parameters has been established,which describes the internal parameters with constant model to correct CCD sensors distortion and describes the external parameters with a orthogonal rotation matrix to compensate external systematic error.On this basis,an in-flight geometric calibration model of look-angle is established which introduces look-angle as internal calibration parameters and external calibration parameters are described as 1st order polynomial exterior azimuth elements.In-flight geometric calibration experiments have been done with different model,different method and different distribution control points,the result verified the effectiveness and correctness of the method.