Aerial Photoscanning with Ground Control Points from USGS LiDAR

Aerial photoscanning is a software-based photogrammetry method for obtaining three-dimensional site data. Ground Control Points (GCPs) are commonly used as part of this process. These control points are traditionally placed within the site and then captured in aerial photographs from a drone. They are used to establish scale and orientation throughout the resulting point cloud. There are different types of GCPs, and their positions are established or documented using different technologies. Some systems include satellite-based Global Positioning System (GPS) sensors which record the position of the control points at the scene. Other methods include mapping in the control point locations using LiDAR based technology such as a total station or a laser scanner. This paper presents a methodology for utilizing publicly available LiDAR data from the United States Geological Survey (USGS) in combination with high-resolution aerial imagery to establish GCPs based on preexisting site landmarks. This method is tested and compared to accuracies achieved with traditional control point systems.