The Measurement Research Of Digital Camera Calibration In Monitoring Of Hefei Urban Rail Traffic With The Digital Close-range Photogrammetry

Under the background of national infrastructure of passion, we are launching the pace of urban rail transit construction in Hefei, Anhui Province. The city is planning a construction of the early 5 lines, later gradually perfects the feeder. Among them, the station interval excavation engineering is the top priority of urban rail transit project, the pros and cons of foundation pit engineering is directly related to the stand or fall of urban rail transit. In recent years, however, to the foundation pit engineering accidents caused by the other, therefore, Hefei Municipal People’s Government are paying lots of attention on those special emphasis on rail transportation foundation pit deformation monitoring and security maintenance. Modern rail transit construction request follow the construction principle of fast, high quality, high efficiency, but also must be based on the safety, the traditional deformation monitoring can meet the above requirements.In order to overcome the shortcomings of traditional deformation monitoring, people begin to pay close attention to the digital close shot photogrammetric method. In recent years, with the continuous development of the digital camera, image processing technology and the continuous improvement of the photogrammetric theory, close shot photogrammetric technology in the field of rail engineering safety monitoring use has received widespread attention. To solve these problems, with the close shot photogrammetric technology is playing an increasingly important role in deformation monitoring, especially the emergence of digital SLR camera, provides a new method for measuring deformation. The close shot photogrammetric technology to track engineering measuring point, obtain useful data in different periods of pictures, and then through the program can calculate the measuring point displacement. That method has these advantages, makes close shot photogrammetric technology is suitable for rail transit foundation pit deformation monitoring, also can be taken in the proper distance is dangerous goal, improves the safety factor, especially when the object is some special monitoring body, in this paper, the foundation pit on rail transportation as an example to study.In this paper, we take care of the project cases under construction, considering the characteristics of underground-excavation engineering; put forward the fast, high quality and high efficiency for the measurement method of camera calibration results. We focus on the methods of traditional camera calibration, and analyze the 2D-lattice method of camera calibration. We are going to implement the process through computer programming, and then calculate the camera parameters. At last, we compare the calculation of the data to the result of the relatively mature and stable close shot photogrammetric software Lensphoto2.0 to prove the feasibility of this method. However, this paper also puts forward some problems to prospect the future research work.