3D-imaging laser scanner for close-range metrology

This paper presents a 3D-Imaging Laser Scanner (3D-ILS) for close range survey for up to 10 meters. The 3D-ISL is eyesafe and works with a visible semiconductor laser diode transmitting at 670 nm. The large ranging dynamic is achieved by measuring the phase difference between the transmitted and received intensity modulated signal. Due to the high modulation frequency of 314 MHz measurement accuracies about 0.1 mm are possible with high measurement rates. Besides the slant range, the system detects laser light backscattered from the object surface under survey. This means that three dimensional images are obtained, if the scanner moves the laserbeam line by line across the object's surface. After explaining the functioning of the 3D-ILS and calculating the theoretical slant ranging performance, typical application examples will be presented which verify the theoretical results and demonstrate the wide application field for the laser scanner which is e.g. CAD, CAM, rapid prototyping, close range-, industrial- and architectural-survey. An application highlight is the survey of a reconstructed skeleton of a dinosaur.