Comparing the Accuracy of Image Based Scanning Techniques to Laser Scanners 2018-01-0525

Accident reconstructionists will typically document scenes, evidence, vehicles or objects of interest by using 3-dimensional laser scanners. These techniques are well documented, utilized and can be extremely accurate. However, when the subject of documentation involves surfaces that include intricate, highly reflective, and/or complex geometry (motorcycles, wheelchairs, stairs, etc.) the commercially available laser scanners can produce obscuring dense stray and scattered points which results in point clouds that could require tedious manual registration and/or optimization. This paper compares a FARO Focus laser scanner, Pix4DMapper, and Agisoft’s Photoscan point cloud data to FARO ARM measurements of vehicles, other transportation devices and architectural features. It was shown that the Pix4DMapper and Agisoft’s Photoscan point cloud data resulted in detailed and accurate point cloud data compared to the FARO ARM measurements. Additionally, the input data for Pix4DMapper and Agisoft’s Photoscan is easy to capture and required minimal processing and did not require extensive, time consuming, optimization of individual scans. This paper demonstrates the use of contemporary photogrammetry softwares, Pix4DMapper and Agisoft’s Photoscan, as accurate, time and cost effective alternatives to laser scanners.