Research On Error Analysis For Target Location Of Single-line-Array CCD Stereo Images

Single-line-array CCD stereo images are widely used in surveying and mapping with the rapid development of the space remote sensing and photogrammetry technology. Single-line-array CCD camera has become an important development direction of high-resolution mapping satellite because of its advantages of simple structure, small size and light weight. This paper focuses on space photogrammetry without ground control points. The development trends of high-resolution mapping satellites, stereotactic model and error analysis at home and abroad is analyzed. The errors analysis for target location of single-line-array CCD stereo images is deeply researched. Geometric distortion caused by measurement error of image and the on-orbit geometric calibration methods is analyzed. The main work of this paper includes:(1) Basic principle of space photogrammetry without ground control points is expounded. The comparison of mathematical model used in photogrammetric between single-line-array CCD image and frame image is made. The target location model without ground control point is analyzed. This provides theoretical basis for the following accuracy analysis.(2) The estimation formulas of target location accuracy for cross-track stereo and along-track stereo are both derived and verified separately based on the characteristics of single-line-array CCD image photogrammetry. Error sources effect on the target location error is analyzed. The variation of target location error with the main error sources is presented based on the model. In order to reduce target location error measurement error of image and on-orbit geometric calibration method of camera are researched. The measurement error of image and inner orientation element cannot be ignored. The error of image angle is remarkable to target location error.(3) Aiming at the characteristics of measurement error of image, geometric distortion is researched. Based on the analysis of effect factors of geometric distortion, a geometric distortion simulation model was established from the physical formation of geometric distortion. Geometric distortion error of the whole imaging chain can be analyzed using this model.(4) Inner orientation element and included angle between star sensing device and single-line-array CCD camera will change, when the satellite is on orbit. Therefore, on-orbit geometric calibration is required. According to the characteristics of single-line-array CCD photogrammetry, an improved on-orbit geometric calibration method is proposed. Relevant simulation experiments are designed. The results of experiment show the feasibility of this method.