The Forensic Audio, Video and Image Analysis Program, Digital Forensic Analysis Unit, Federal Bureau of Investigation, Quantico, Virginia, USA.
Resolution Video Inc., Fredericksburg, Virginia, USA.
J Forensic Sci. 2022 Jan;67(1):188-199. doi: 10.1111/1556-4029.14891. Epub 2021 Oct 8.
Reverse projection photogrammetry has long been used to estimate the height of an individual in forensic video examinations. A natural extrapolation would be to apply the same technique on a video to estimate the speed of an object by determining the distance traveled between two points over a set amount of time. To test this theory, five digital video recorders (DVRs) were connected to a single fixed camera to record a vehicle traveling down a track. The vehicle's speed was measured through Doppler radar by a trained operator and the speedometer of the vehicle was also recorded with a video camera. The recorded video was examined and the frames that best depict the beginning and end of the vehicles course were selected. Two reverse projection photogrammetric examinations were performed on the selected frames to establish the position of the vehicle. The distance between the two points was measured, and the time elapsed between the two points was examined. The outcome provided an accurate speed result with a standard degree of uncertainty. This study proves the feasibility of using video data and reverse projection photogrammetry to determine the speed of a vehicle with a limited set of variables. Further research is needed to determine how additional variables would impact the standard degree of uncertainty.
反向投影摄影测量法长期以来一直被用于法医视频检查中估计个体的高度。一个自然的推断是，通过在视频上应用相同的技术来确定在设定的时间内两点之间的行进距离，从而估计物体的速度。为了验证这一理论，将五个数字视频记录器 (DVR) 连接到一个固定摄像机，以记录车辆在轨道上行驶。通过受过训练的操作员使用多普勒雷达测量车辆的速度，并用摄像机记录车辆的速度表。检查记录的视频，并选择最能描绘车辆行驶起点和终点的帧。对所选帧执行两次反向投影摄影测量检查以确定车辆的位置。测量两个点之间的距离，并检查两个点之间的时间流逝。结果提供了准确的速度结果，具有标准的不确定度。本研究证明了使用视频数据和反向投影摄影测量法来确定具有有限变量的车辆速度的可行性。需要进一步研究如何增加其他变量会影响标准不确定度。
