Research On Close-range Photogrammetry Based On Non-metric Digital Camera

Along with the stepwise developing of photogrammetric technique, digital photogrammetry which is based on digital image and photogrammetric foundation has replaced the traditional mapping measure of photogrammetry, and it has been being wildly popularized and applied. Based on original critical research results, we did some research on image processing and photogrammetry processing, and it introduced the following results:1. The image of the circular target appeared as an ellipse because the target plane could not be completely parallel to the image plane. There is an impossible deviation between the image of circular target center and the center of the ellipse imaging if the circular target is oversized. In order to find the rule and the relation between the deviations, and to find the offset correction method, we discussed from the collinear condition equation of photogrammetry,the ellipse fitting is based on least square algorithm ,and finally found out the deviation correction formula, the distributed rule and the relations of the deciation.2. The article introduced the method of using four-dimensional algebra to describe the rotation matrix, and went into particulars to use this method to calculate the exterior orientation elements by the P-H arithmetic or the unit quaternion arithmetic, and compared with the traditional method in astringency among the operation process. The test proves the reliability and stability of these two algorithms in the application of Close-rang Photogrammetry. The paper also shows that using four-dimensional algebra to describe the method of rotation matrix is flexible, this method can ensure the constringency and gets well result in various instance, and has the advantages of fewer times in iteration, and steady result in calculation and so on, because of trigonometric function's operation being averted in the adjustment.3. In the experiment,we used an ordinary digital camera to get objects' images, 3D control field is then be used to determine lens distortion of the digital camera. Because there is big distortion between images, we used the fundamental matrix match technique based on robust estimation to match the matching points. This paper integrates with the actual need of work,we researched some image matching technique that adapt to Close-range Photogrammetry.4. In the reach of relative orientation arithmetic,we compare the P-H arithmetic with the traditional arithmetic. We also analysed the image poits of different case that used in the relative orientation. The results show the reliability and stability of P-H arithmetic, it also shows that using P-H arithmetic to describe the method of rotation matrix is flexible, the trigonometric function's operation is being averted in the adjustment ,so we can ensured the constringency and got well result in various instance.5. In the experiment,the paper shows the precision by using image data processing from ordinary digital camera.