Project Images Southern Illinois Airport Obstruction Survey Project Summary The Southern Illinois Airport Authority chose Hanson to provide engineering, planning and special services for the removal of trees that had become an obstruction to Runway 6 at Southern Illinois Airport in Murphysboro, Illinois. The project included removing the trees with non-disruptive methods and implementing temporary and permanent erosion control measures; conducting an on-site observation of the existing conditions to evaluate potential factors affecting the project design and construction; preparing a categorical exclusion checklist to meet National Environmental Policy Act requirements; coordinating proposed improvements with the sponsor, state, Federal Aviation Administration, local regulatory agencies and affected airport tenants; assisting the airport as its resident project representative; environmental mitigation; and construction plans and specifications. This project benefitted from Hanson’s unmanned aircraft system (UAS), more commonly referred to as a drone, which was used to conduct pre- and post-removal obstruction surveys. As a part of the design phase, Hanson conducted an aerial survey with its UAS to identify obstructions within the Runway 6 approach. This process included collecting geolocated aerial imagery, which was used to produce a 3D point cloud. By employing this technology, survey points were generated roughly every 2 inches over the approximately 145-acre area. These points were analyzed to identify areas where the tree canopy penetrated the approach surface. Based on this analysis and additional field verification through traditional surveying means, tree removal limits were established. After construction concluded, Hanson again employed its UAS technology to verify that all obstructions had been removed and to photograph the construction area. By analyzing the 3D point cloud generated from the aerial imagery, Hanson verified that all trees within the limits had been removed. The aerial imagery also served as an as-built record, showing all trees that had been removed and the post-construction site conditions, given the environmental nondisruptive limitations placed on this project.