Ordinary Digital Camera Close-range Photogrammetry Accuracy Of Multi-baseline

Close-range photogrammetry comprehensive theory and method of digital image processing, computer technology, pattern recognition, image matching and other disciplines; is the basic principle of image processing based on Digital Photogrammetry and; is the photogrammetry that extracts the geometric and physical information of objects using mathematical methods.With the devolopment of the digital close-range photogrammetry, it has been applied in many areas, such as dynamic object trace measuement, deformation measurement of complex tall buildings, the object model construction. To get images more effectively, and to calculate images to achieve the required accuracy have been the focus in the study of digital close-range photogrammetry.In digital photogrammetry to acquisite digital image, a professional photographic equipment is normally used. These professional equipments are expesive that non-professional departments are unable to apply.With the development and progress of digital camera technology,the ordinary digital camera in the field of digital photogrammetry is widely used, especially in the digital close-range photogrammetry, the application of Low-altitude UAV Photogrammetry showed a huge advantage. Ordinary digital cameras are not only cheap, and easy to operate, a professional camera can’t match. Along with the advance of digital camera technology and constantly improved picture formate and resolution, digital camera with respect to the professional camera’s advantage is more prominent.This paper studies on close-range photogrammetry of multiple baseline non-metric digital camera, by adopting the method of three-dimensional measurement, using multi-baseline stereo matching technology to obtain a high precision fixed-point model (PM) data, through the bundle adiustment to locate target mainly including Parameter calibration of non-metric digital camera, relative orientation of image pair,Multiple model merging, Regional network for bundle adjustment based on Non-metric digital imagery, and The free network adjustment without control points and Multi-baseline stereo matching strategy.The development, research status and applications in current social situation of close-range photogrammetry are detailed. Indroduced the working principle, classification and the performance index of a digital camera. In close-range photogrammetry, the relations between defferent coordinate system, relations between the idside and outside location factors of photos and these coordinate system are devoted. Cautions of camera calibration and method of camera self calibration are stated. Calculated Direct Linear Transformation (DLT), remind of how to establish a reliable practical measurement scheme, if the object can not be completely photographed.In this paper the multiple baseline non-metric digital camera close-range photogrammetry accuracy is focuses on, multi-directional, multi-angle photos, using Lensphoto multiple baseline measurement software to fixed-point (model) were measured and analyzed.Various factors influence the accuracy of close-range photogrammetry. The same camera different intersection angles, different shooting distance, different cameras with different resolution, precision of control point, control point distribution in different situations, different number of control points, these are analyzed and compared in detail.The experiment indicats close-range photogrammetry accuracy increases as the intersection with the resolution increases, control point rises. Accuracy of equally distributed control points and measuring points is relatively high. If the shooting distance is farther, the measuring precision can be improved by increasing the resolution.