LiDAR Drone Technology for Forensic Applications in Forested Areas Shows the Most Detail with Triple Returns

Abstract

LiDAR (Light Detection and Ranging) technology has become prevalent in forensic science as a way to document and investigate crime scenes. Using drone LiDAR, scientists are able to rapidly and accurately scan large areas to increase efficiency when collecting data. The data captured by drones also enables scientists to create 3D models that can be used in court. While the L1 LiDAR sensor has an accuracy of about 10 cm in open air at 165 ft, this sensor can also be used in forested areas to look through the trees to give a look at a potentially inaccessible crime scene; however, this field has not yet determined the accuracy with capturing LiDAR data in these areas. For this experiment, an object with a length of 0.61 m and width of 0.36 m was placed on the edge of a forested area. Measurements were taken with a LiDAR DJI L1 scanner with single and triple returns at an altitude of 180 ft, speed of 2.7 mph, and 70% front and side overlap. Flight data showed the object, and using a scale of the open sidewalk, the length and width were calculated at 0.50 m and 0.25 m respectively. The percent error for the length is 18%, while the percent error for the width is 31%. Given the somewhat high percent errors, the next step should be to compare this scanner with the L2 scanner or other LiDARs to further explore the accuracy in wooded areas.