LIDAR Scanning

January 15, 2013 Expert Tips


Not that long ago, accident reconstruction was defined by a police investigator with a tape measure, ruler and a pencil. He would measure out the site, gathering a dozen or so points of information – so many feet to the curb, so many feet between the two cars, etc – and recreate the scene on a sheet of paper. Then came a major upgrade – the tripod-mounted laser. An accident investigator would swivel the laser back and forth, gathering multiple points of exact information which would be used to generate a virtual 3D environment.

3D environments have created a revolution in forensic accident reconstruction and provide an exceptional tool for investigators, attorneys and mediators. No longer is the recreation constrained to a two-dimensional plane of paper in which time and motion are denoted by arrows. A skilled reconstruction technician can build a computer-animated sequence within a photo real world that depicts all the moving parts of an accident at their actual speeds from any angle desired.

As exceptional as these 3D constructions are, the main watchword for them is admissibility. They are useless if a judge will not accept them into evidence. That hinges entirely on the technician’s skill and the value of the data he has to use: the points gathered by the investigator. And that leads to the expanding use of an extraordinary technology: LIDAR Scanning.

LIDAR – (Light Detection And Ranging) – is a remote sensing technology that uses laser pulses to measure the distances to objects in a full 360 degree sweep. A tripod-mounted machine barely larger than a pair of shoes uses a horizontally-rotating head coupled with a vertically-tilting mirror to scan the area around it. In doing so, it gathers not just dozens but millions of points – known as a point cloud – from which a reconstruction technologist can build an unimpeachably correct 3D environment. Within this environment, one can zoom in and out, change angles, move forward or backward, all with the goal of allowing the clearest possible understanding to a jury.

Accident reconstruction has come a long way from the tape measure and the pencil. 3D animation powered by LIDAR Scanning provides an irrefutable data set that greatly improves the likelihood of an animated sequence’s acceptance into a court of law.