DASH CAMERA VIDEO VELOCITY ANALYSIS Adam Cybanski Gyro Flight & Safety Analysis Inc.
O
verview On 20 June 2018, a vehicle performance engineer from the Office of Research and Engineering at the National Transportation Safety Board (NTSB) met with the founder of Gyro Flight & Safety Analysis in Ottawa, Canada. Dash camera refresher training was conducted and covered a variety of topics including frame extraction, frame rate calculation, lens distortion, focal length estimation, tracking, geoidentification and solving camera motion.
The author (Adam Cybanski) carried out live testing in the area. As part of a practical exercise, he drove down a stretch of road for speed testing. This was captured using a dash camera, and a racing quality GPS. An initial analysis of the dash camera footage was conducted during the refresher training. Comprehensive camera analysis followed over several months, and is now provided below in order to compare the velocities extracted from dash camera video, with the high-performance GPS data. 16 Collision Magazine - Volume 13 Issue 1
Volume 13 Issue 1.indd 16
Background
As an aircraft accident investigator, Adam Cybanski has been extracting velocity information from witness video since 2008. Cockpit cameras, similar to dash cameras, ramp cameras similar to traffic cameras, and handheld witness video were photogrammetrically analyzed in order to derive the velocities of the cameras, and the vehicles seen in the field of view as part of aircraft accident investigations. In 2015 the author also started assisting the local police with investigations of traffic accidents that were caught on video. The techniques developed for analyzing video of aircraft accidents are now employed for traffic accident reconstruction. Velocity analysis from witness video is based on three workflows: matchmoving, geoidentification and time-distance. Matchmoving is the calculation of camera and object position from video. Geoidentification involves identifying references from a video in real world coordinates (lat/long, UTM grid). Time-distance requires analysis of
www.collisionmagazine.com
5/28/2019 9:34:23 AM
