UAV Survey-Grade Topographic Mapping
Wohnrade Civil Engineers, Inc. has perfected a workflow for the preparation of survey-grade topographic mapping which can be used for civil engineering design.
The workflow requires expertise in several disciplines including: GIS, surveying, CAD technology, photogrammetry, and aeronautics. Both fixed-wing and multi-rotor UAVs enable aerial data collection for sites with a wide variety of terrain.
The Black Cloud Tailings Storage Facility in Leadville, Colorado was flown on June 8, 2016. Surveyed ground control points were used to prepare a survey-grade topographic map of the 104 acre site, which is located at an elevation of roughly 11,000-feet. A point cloud containing over 222 million points was generated, with each point representing 1.5 square inches on the ground.
The final deliverable included a high-resolution orthomosaic image, digital surface model, and contour mapping with a contour interval of one-foot (image below). It is possible to create a contour interval of 0.10-feet, if required.