Calibration experiments of a laser scanner
Geraldine S. Cheok, Stefan D. Leigh, Andrew L. Rukhin · 2002
The potential applications of laser scanners or LADARs (Laser Detection and Ranging) are numerous, and they cross several sectors of the industry -construction, large-scale manufacturing, remote sensing, national defense.A LADAR is an instrument which can rapidly capture 3-D data of a scene in the form of x, y, z points.The confidence in end products of the applications -3D models, positioning, derived quantities -depends largely on the accuracy and precision of the laser scanner.For global uncertainty analysis via error propagation, specific instrumental uncertainties need to be determined.This report chronicles exploratory experiments conducted at the National Institute of Standards and Technology to characterize a LADAR, focusing on accuracy and precision.The specific variables considered were distance, angle of incidence, and target color.Other characteristics of the LADAR such as the returned intensity and beam divergence were also examined.Initial findings indicate no obvious global color effect on accuracy although range-specific biases were observed.Decreased measurement accuracy is observed for higher angles of incidence.Reflectivity contributes to measurement error with highly reflective targets exhibiting large errors in the shorter ranges and low reflective targets being less precise in the longer ranges.These initial efforts are expected to contribute to the understanding of what is required to calibrate similar sensors in terms of significant parameters, test procedures, and calibration facility requirements.