<title>Measuring structural displacements and deformations in long distance by CCD high-accuracy position detection</title>

Abstract

In this paper, a CCD position detection system for measuring the displacements and deformations of structure is introduced. This measurement method is based on the position detection technique of digital images. A bright spot is fixed on the object measured and imaged to the target of CCD camera by a telescopic lens. The CCD target converts the optical information into equivalent electric signal. The video frequency signal is digitized into an array of 512 X 512 pixels by the analog-to-digital converter and then transmitted into the microcomputer. The computer controls the data acquisition system performs image processing and detects the position of spot. Comparing the position with original position of spot, the displacement of object is obtained. By using high accurate position detection software the accuracy of detection is up to 0.01 mm in 6 m distance between the object and the observation point, the distance can extend to 100 m and farther.