Accuracy and Validation of 360-Degree Camera Use in Photogrammetry
2022-01-1003
03/29/2022
- Event
- Content
- Accident scene data obtained from photographs and videos are vital material for forensic analysts. They allow to precisely determine the orientation and location of evidence as seen on such images. For that reason, the term digital evidence was adopted and is commonly used among analysts in conjunction with retro-projection methods as an aid to reconstruct the events and inputs leading up to the investigation in question. Photogrammetry is a retro-projection method commonly used by analysts to match scene photographs with calibrated control points obtained from three-dimensional point cloud data collected at the subject site and visualized on the scene images. From this merger, the photographs allow for the determination of the point at which the camera was positioned that took the subject image. In general, the point cloud data allows for increased accuracy during the photogrammetry process. Video footage obtained from the scenes can be exported as frames and then used in the same manner as digital images in photogrammetry. 360-degree cameras are a relatively new type of camera that can capture their entire surroundings by having multiple wide-angle lenses. The research and testing presented in this study intends to rectify the perspective and lens distortion issues presented by 360-degree cameras and justify their usage in photogrammetry. The present study considered several models of 360-degree cameras of varying specifications, performance, and cost. All cameras were either positioned in the same location and in the same orientation as each other or were moved along the same path and in the same orientation as each other. Point cloud data of the test site was obtained using a Leica RTC360 Laser Scanner. The same point cloud data was used in the photogrammetric analysis for each camera. Testing was conducted outdoors in natural light, as it would be during typical forensic investigative procedures. Several different test scenarios were conducted with the 360-degree cameras. Distances between designated test objects were physically measured and used as a benchmark to the distances determined by point cloud photogrammetric analysis. The distances between the designated test objects were large enough to be considered appropriate for typical accident reconstruction analyses. A distance comparison was made against the physically measured benchmark distance for each 360-degree camera, as well as against the point cloud data.
- Citation
- Morales, R., "Accuracy and Validation of 360-Degree Camera Use in Photogrammetry," SAE Technical Paper 2022-01-1003, 2022, .