Research On Key Technologies Of Ortho-correction Based On Aerial Remote Sensing Images

In the imaging process of remote sensing images, due to some factors, for example, perspective projection, title photography axis, atmospheric refraction, earth curvature and terrain effects, resulting in different degrees of geometric deformation and distortion toward each pixel in the image. The orthophoto images not only eliminates each factor which led to the distortion of image, but also includes the richer and more vivid visual information than line graphy. Therefore, In remote sensing applications, how to quickly produce orthophoto images is become an indispensable work.In the produce of making orthophoto images, it is essential which inner orientation elements of aerial camera and exterior orientation elements while the shooting time, so we should research the theory and method of acquiring.The paper first discusses the inner orientation elements of aerial camera (the forcal length and main forcal point coordinates) and the calibration method, and then describes how to use the POS system of airborne to acquire high-precision exterior orientation elements (the aircraft attitude and geographic coordinate data corresponding to acquisition time of aerial remote sensing image ), on this basis, make use of LPS module of ERDAS 9.1 (Leica Photogrammetry Suite) to ortho-correct aerial remote sensing image which acquire from the expriment .In order to acquire precise inner orientation elements of aerial carema, it is essential that the geometric calibration of aerial camera (inner orientation elements and the optical distortion), in the second chapter, first introduce the calibration content and method of inner orientation elements, and then introduce the calibration method and principle which based on indoor three-dimensional calibration field, through the space resection based on single image and multi-images, calculate the inner orientation elements, lastly verify and analyze the calibration results.In order to acquire precise exterior orientation elements of exposure time, not only should thoroughly and in detail familiar with the POS system, but also include the aerial remote sensing experiment, in the third chapter, discuss IMU/DGPS, include system structure, basic principles, basic methods, precautions and error analysis; in the fourth chapter, discuss the aerial remote sensing experiment which based on IMU/DGPS, include test preparation, test implementation, data analysis, test summary and so on.