In very basic terms, high-definition surveying [3D] laser scanning is the next generation of accurate, fast, comprehensive data collection. Classic total-station survey equipment collects data points one at a time, while the 3D laser scanners collect millions of data points in just minutes. The dense “point cloud” data collected by the laser scanner creates an accurate, three-dimensional model of everything that the beam reflects off of. The two most common types of scanners utilized in the industry are short-range scanners, typically utilized for a focal distance of less than 1 meter, and mid and long-range scanners, typically utilized for a focal distance of greater than 2 meters. A single scan with some long range scanners can record reliable data, accurate to within 0.25 inches, up to about 300 feet away.
3D laser scanning is utilized for any application that requires accurate preservation of 3D data. Examples include land surveying; the documentation of buildings and facilities that no longer have accurate blue prints for use in maintenance, repair and additional construction; and historical preservation purposes. In the forensic area, the uses of 3D laser scanning are as varied as the type of cases. Forensic uses of 3D laser scanning includes documenting objects the size of skyscrapers to those smaller than footprints.
Long-range scanners are effective in expeditiously and accurately collecting data from buildings, bridges and roadways, among other large objects. Mid-range scanners are useful for scanning medium-sized objects like vehicles and machinery. Their effective range is approximately 50 feet. Close range scanners are utilized when you need to record finer details in objects such as tire tread marks or footprints. In forensic work, the investigator often has a limited amount of time in which to collect data. As such, the selection of the proper scanner may be critical in accurately collecting the most comprehensive data over the shortest amount of time.
Today, the 3D laser scanner not only takes significantly more data points than any other method, the use of the laser scanner takes the “selection” process (of what data to collect) out of the mix. The scanner will collect data indiscriminately off of any surface that the laser beam will reflect. The ability to collect such comprehensive 3D data in a relatively short amount of time provides an unprecedented amount of accurate and detailed data, without having to “think” about what to collect and not collect. Accurate three-dimensional field data can be utilized in place of expensive and time-consuming “scene” re-creations.
3D laser scanning provides the ability to create quickly, and most importantly with unprecedented accuracy, a 3D environment in which to view an event. Additionally, the accurate, to-scale 3D environment can (and is) utilized as the palate on which the scientific/engineering analysis can be performed and ultimately shown to those involved in the matter- from the adjusters, to the attorneys, to the experts, to the opposing side, and to the Trier-of-Fact.
If you’d like to learn more about 3D laser scanning, please give us a call at 800-332-6273 or you can find a list of upcoming industry meetings and events at Wohlers Associates.