期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2006
卷号：XXXVI Part 5
出版社：Copernicus Publications
摘要：Optical triangulation methods based on a laser light sheet and digital camera are used as a surface measurement technique in a wide range of applications. They allow a fast and accurate determination of surface profiles, while consisting of relatively simple hardware and software configurations. The definition and analysis of surface profiles on reflective materials plays an important roll in experimental hydromechanics. The Institute of Photogrammetry and Remote Sensing (IPF) at Dresden University of Technology, in cooperation with the Federal Waterways Engineering and Research Institute (BAW), initialised a project to develop and implement a method to measure water-surface profiles based on laser light sheet projection. As the developed system will be installed and used in a laboratory to capture moving water surfaces, a registration and recording of dynamic phenomena is requested additionally. The study presented in the paper describes a further development of the optical triangulation based on laser light by using reflection properties of mirror-like surfaces. For this task, a laser sheet is projected onto the water surface and reflected onto a set of two vertical planes, which are arranged parallel behind each other. The resulting laser lines are observed by a camera and measured by subpixel operators. Water surface level and gradient can be derived from these lines by using a mathematical model, which was developed at IPF. The integration of a step motor to vary the incidence angle of the laser plane allows on the one hand the efficient calibration of the whole system and on the other hand the sequential measurement of different surface profiles from one system position. In this configuration, the temporal dynamic of the surface variation is just limited by the frame rate. The article presents the basic principle, potential and limitations of the method. Besides the geometrical and mathematical model, the procedure of a strict system calibration is outlined, and the results of a practical test are shown and discussed
关键词：Triangulation; Water Surfaces; Laser Light Sheet
