Characterization of a Range Scanning System Utilizing a Point Laser Rangefinder

This thesis presents an error characterization scheme with application to a pulsed timeofight laser range nder called the AccuRange 3000. Characterizations of range-imaging sensors are important because they determine the limitations of the sensor. Also, characterizations are the rst step in developing a correction model for range data and they provide information about the amounts of error present in the data to aid in post-processing techniques. The combination of all these factors provide a basis for making a decision on which type of sensor to use for a particular application. First, the thesis reviews range imaging sensor technology. This review is followed by a discussion of previous work in the areas of characterization of laser range nding systems and error models of laser range nders. A technical description of the pulsed time-ofight laser range nder coupled with the mechanical scanning system we use for data acquisition is given. Also, this thesis details a simulation of the entire system developed using Telegrip simulation software. The thesis gives an error characterization of the laser range nder utilized as a point laser. This includes errors associated with temperature, sampling rates, mixed pixels, varying values of re ectance at incremental distances and varying values of re ectance at incremental angles of incidence. Selected information gathered during these experiments are combined to form a correction model of the laser system. This correction model is based on the range and intensity data output from the laser range nder. A comparison of corrected and uncorrected range values is given for several data sets. Also, a con dence metric is derived and given for each corrected range value. The con dence metric is an estimation of how much error is present in the corrected value. The thesis concludes with a discussion of the results and possible extensions for future work.