Integrated laser scanner and intensity image calibration and accuracy assessment

Abstract

Nowadays, the use of laser scanner devices as an active technique for acquiring 3D information is growing fast. The huge amount of object points produced with less effort than other 3D acquisition techniques is one of the reasons for interest. For accurate measurements a sophisticated sensor model and calibration procedure is an important prerequisite of such an efficient system. Thecalibration and accuracy assessments of the measurement system reflect the reliability and correctness of the system output. For the calibration and accuracy assessments of the laser scanner system we use the laser’s intensity image and a sensor model,which we developed by extending our mathematical model for linear array based rotating panoramic cameras. The sensor model describes substantial deviations from the pinhole model using additional parameters. With additional parameters the following errors in laser scanners can be modeled: eccentricity of the scan center, collimation and horizontal axis error, tumbling error and resolution of horizontal and vertical rotation. In this paper we present the results of calibration with additional parameters for the Imager 5003 of Zoller+Fröhlich GmbH, which indicate a subpixel accuracy level for such a highly dynamic system. Finally we will demonstratethe system’s accuracy in 3D point positioning by means of a testfield. The result shows the efficiency of our approach for laserscanner modeling.