VirtuaLot—A Case Study on Combining UAS Imagery and Terrestrial Video with Photogrammetry and Deep Learning to Track Vehicle Movement in Parking Lots

Abstract

This study investigates the feasibility of applying monoplotting to video data from a security camera and image data from an uncrewed aircraft system (UAS) survey to create a mapping product which overlays traffic flow in a university parking lot onto an aerial orthomosaic. The framework, titled VirtuaLot, employs a previously defined computer-vision pipeline which leverages Darknet for vehicle detection and tests the performance of various object tracking algorithms. Algorithmic object tracking is sensitive to occlusion, and monoplotting is applied in a novel way to efficiently extract occluding features from the video using a digital surface model (DSM) derived from the UAS survey. The security camera is also a low fidelity model not intended for photogrammetry with unstable interior parameters. As monoplotting relies on static camera parameters, this creates a challenging environment for testing its effectiveness. Preliminary results indicate that it is possible to manually monoplot between aerial and perspective views with high degrees of transition tilt, achieving coordinate transformations between viewpoints within one deviation of vehicle short and long axis measurements throughout 70.5% and 99.6% of the study area, respectively. Attempted automation of monoplotting on video was met with limited success, though this study offers insight as to why and directions for future work on the subject.

Keywords

• monoplotting
• photogrammetry
• computer vision
• object detection
• object tracking
• neural networks