A laser scene scanner is only the latest example of a technology being used by NTSB accident investigators. Laser scanning brings virtual reality into our investigations. Whereas “old-fashioned” photography can accurately depict an accident scene or vehicle in two dimensions, laser scanning can accurately depict that same scene in three dimensions.
NTSB investigators within the office of Research and Engineering record three-dimensional data of accident objects by placing the laser scene scanner on a tripod, where the scanner will rotate 360 degrees. While automatically rotating to investigate its entire surrounding environment, the scanner emits a laser beam out to a range of about 300 feet. By keeping track of its position and orientation and measuring the time it takes for the laser beam to reflect off objects, the scanner can create a three-dimensional view of its surroundings.
The scanner cannot capture an image of the backside of any object. To completely capture scenes, NTSB engineers use special targets and place the scanner in various positions of a scene to capture multiple scans. NTSB engineers then stitch together the multiple scans to create a complete three-dimensional representation of a vehicle or accident scene, such as long sections of highway or railway. NTSB engineers can precisely measure tire skid marks, deformations in damaged vehicles, and other important features from accidents.
Three-dimensional data obtained from a laser scene scanner also can be used to create full-color still images and computer simulations. Computer simulations created from data recorded by laser scene scanners are particularly helpful to replicate the accident environment back to the NTSB’s state-of-the-art laboratories in Washington. Imagine yourself within a movie set and placing a camera anywhere in the scene to view objects. With a computer simulation, you can observe an accident scene from any available vantage point and “walk” through an accident scene by moving the camera through the environment. These simulations can be used to study the accident environment as seen by an operator of a vehicle before or during an accident.
The laser scanner is just one piece of technology necessary to fully support accident investigations that lead to improvements in transportation safety for the public.
Joseph Kolly is Director of the Office of Research and Engineering