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Determination of average vehicle speed utilizing reverse projection
Walter E Bruehs1, Dorothy Stout2
1The Forensic Audio, Video and Image Analysis Program, Digital Forensic Analysis Unit, Federal Bureau of Investigation, Quantico, Virginia, USA.
Journal of Forensic Sciences
|October 8, 2021
Summary
Reverse projection photogrammetry can accurately estimate vehicle speed from video data. This forensic technique determines distance traveled over time, offering a reliable method with a known degree of uncertainty.
Area of Science:
- Forensic Science
- Photogrammetry
- Video Analysis
Background:
- Reverse projection photogrammetry is established for estimating human height in forensic video analysis.
- Extrapolating this technique to measure object speed from video is a logical progression.
Purpose of the Study:
- To investigate the feasibility of using reverse projection photogrammetry to determine vehicle speed from video recordings.
- To assess the accuracy and uncertainty associated with this method.
Main Methods:
- Five digital video recorders (DVRs) captured a vehicle's motion on a track.
- Vehicle speed was cross-validated using Doppler radar and an onboard speedometer.
- Reverse projection photogrammetry was applied to selected video frames to calculate distance traveled.
Main Results:
- The study yielded an accurate vehicle speed estimation.
- A standard degree of uncertainty was quantified for the results.
- The feasibility of the technique was demonstrated under controlled conditions.
Conclusions:
- Video data combined with reverse projection photogrammetry can reliably determine vehicle speed.
- The method is effective with a limited set of variables.
- Further research is recommended to explore the impact of additional variables on accuracy.
Keywords:
accident reconstructiondigital video recordersforensic photogrammetryforensic video analysisframe timingmensurationphotogrammetry analysisproprietary file formatradarreverse projection photogrammetryspeed calculation uncertaintyspeed calculation uncertainty mitigationspeed determinationtemporal compressionvideo analysis
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