LiDAR Drone Technology in Law Enforcement Yields Most Accurate Measurements at an Altitude of 60 Feet

Abstract

In law enforcement, LiDAR technology is used to document and investigate crime scenes. By attaching a LiDAR sensor to a drone, scientists make this method of documentation more accessible and accurate with a quick response time in the field. Drones have become increasingly useful in law enforcement with technology such as photogrammetry, thermal infrared sensors, and most recently, LiDAR sensors. This field is yet to determine the accuracy with capturing LiDAR data with differing drone heights and mapping settings. Flight altitudes affect the point cloud density where lower altitudes yield dense point clouds and more sharp, accurate images (Njambi, 2021). For this experiment, an object with a horizontal length of 0.35 meters and vertical distance of 0.09 meters was placed in a grassy area. Measurements were taken with both single and triple return by a drone LiDAR system with altitudes of 60ft, 100ft, 125ft, and 150ft. The object was detected in all flights with most detailed LiDAR imagery using triple return. Object measurements ranged from a horizontal length of 0.21 meters to 0.38 meters with the differing parameters. Vertical heights measured were not consistent with the object’s vertical height in any flight. Flight parameters of 60 feet triple return with 80% forward and side overlap yielded most accurate measurements of the object with a horizontal length of 0.36 meters.