MARYVILLE, MO, June 1, 2017 – Midland Surveying recently completed a task order for the U.S. Army Corps of Engineers (USACE), Omaha District for the Battalion Infantry at Fort Carson, Colorado utilizing an Unmanned Aerial Vehicle (UAV) to collect LiDAR data and aerial imagery. The project area for the topographic and utility survey included 730 acres of remote terrain, including Range 127 in the Ft. Carson Firing Range Complex. The scope required 1” = 30’ mapping of the area.
Several methods of data collection were considered for this project. RTK terrestrial survey methods would have required 8 weeks of field time and training operations could not be suspended for that length of time. Collecting aerial LiDAR with a helicopter was not possible due to airspace restrictions. Midland Surveying proposed a solution for collecting aerial imagery with a UAV operating below an altitude of 400 feet above ground level (AGL).
Midland Surveying collected data over a 2 day period using our senseFly eBee+ RTK capable fixed winged UAV, with a 20 megapixel S.O.D.A. camera. The site was controlled with 20 photo identifiable ground control target with positions determined by RTK GPS. A field survey crew was onsite during the flight operation to maintain a GPS base for RTK corrections with the UAV, verify the location of planimetric features, and to collect break line points and quality control check points in various ground cover classes.
Although this was not the ideal approach for collecting topographic data in this type of terrain and ground cover, it was the only approach that would meet the client’s time constraints for site access. The overall accuracy results turned out similar to what could have been obtained using terrestrial RTK with break line and spot elevations collected at a spacing of 30’.
This task order was completed through a Nationwide Surveying and Mapping IDIQ Contract with the US Army Corps of Engineers, Omaha District, which was awarded to Midland Surveying in April 2014.