Eugene Liscio, Quan Le, Ryan Rider, & Tilo Voitel
Abstract: FARO Zone 3D (FZ3D) is a relatively new software package designed for crash reconstructionists and crime scene investigators. The program has a feature that allows scaled Google Maps images to be imported into its workspace such that satellite imagery of an area may be measured, traced, or serve as a reference for 3D modeling or animations. This is useful when a site inspection cannot be carried out but is still necessary for reconstructions. An understanding of the accuracy of this method provides reconstructionists and investigators knowledge regarding its accuracy when utilizing FZ3D. This study compares linear measurements taken using Google Maps images with those done with a terrestrial laser scanner. A total of 800 measurements were taken across 8 roadways in North America by 10 participants. The average percentage difference between all laser scanner measurements and participant measurements was 0.894%. The mean absolute error (MAE) for all the data was determined to be 0.350 m (1.148 ft), with a standard deviation (SD) of 0.296 m (0.971 ft). Distance measurements less than 5 m resulted in a large average percentage difference of 8.286%. These findings are comparable to previous studies and are reasonable for the general mapping of large outdoor scenes.