Multiple calibration bench for focal length of cameras by means of laser distance meter

摘要

The calibration of the cameras used in close-range photogrammetry is usually performed using auxiliary elements with known geometry and/or dimensions, through one or several photographs of elements with geometrical restrictions, which enable the calculation of the different parameters needed. This research suggests an improvement in these procedures through the use of one or several laser meters. The method is based on the use of calibration pillars in a laboratory, in which the cameras and laser meters subject to calibration are fixed. The cameras are calibrated by determining the relative positions of all the devices at the same time, which enables the application of the algorithm designed for hybrid laser-camera systems used for measuring in civil engineering and robotics. For this purpose, photographs and measurements are taken by laser meters over a moving object of unknown geometry and dimensions.