Laurence R. Penn, CFVT, Senior Forensic Animation / Video Specialist

When a surveillance camera captured an incident involving a school bus and motorcycle, the forensic science of videogrammetry and three-dimensional accident reconstruction helped determine the speeds of the vehicles and sight lines of the operators leading up to the collision.

Multiple high-density LIDAR scans of the site were captured by DJS Associates field crew to provide millions of accurately measured points from which the frame-by-frame photogrammetry was performed. By correlating many features on the two-dimensional surveillance image to their to-scale positions in the LIDAR scan data, the position and orientation of the camera was recreated in three-dimensional space with a virtual camera. Scans of the bus were also captured and provided measurement data for tracking and plotting its position in the 3D reconstruction.

The motorcycle position was then plotted in the scene for every frame of the camera-matched surveillance video. Additional vehicles moving through the intersection at the time of the incident were also plotted within the videogrammetry analysis. Virtual cameras were placed in the 3D analysis at the approximate height of the vehicle operator views in order to observe possible obstructions or behavior leading up to the impact.

The roadway approaching the intersection follows a hill and as a result, the time and distance the motorcycle was positioned at the crest relevant to the sight line of the bus operator was calculated.

High quality animated renderings were produced from the accident reconstruction analysis to convey forensic engineer opinions.

Laurence R. Penn, CFVT, Senior Forensic Animation / Video Specialist with DJS Associates, Inc., can be reached via email at experts@forensicDJS.com or via phone at 215-659-2010.

Categories: Accident Reconstruction | Camera Matching | Collision Reconstruction | Engineering Animations | Forensic Animation | Photogrammetry | Video Surveillance | Videogrammetry