The project team reviewed scientific, technical, and marketplace
information relevant to using UAS for mapping wetlands along potential road
corridors. This information was synthesized into authoritative guidance on UAS
platforms, payloads, flight operations, and the UAS regulatory environment. In
particular: 1) UAS scouting can aid in identifying wetland extents when areas
are difficult or dangerous to access, 2) very high resolution RGB image
mosaics can be created for expert interpretation and to construct extremely
detailed terrain models for hyper resolution terrain analysis, and 3) techniques
for direct sensing of wetlands with advanced sensors like lidar and radar. Regulatory
and technical limitations currently limit the potential of UAS for wetland
mapping. Most significantly, beyond line of sight operation is forbidden in
most cases, making it difficult to map large areas. When wetlands exist under
closed forest canopy, lidar or radar instruments are the only options for
direct sensing of the forest floor. But, currently available lidar instruments
are expensive, have reduced accuracy compared to traditional systems, require
larger aircraft, and are not tightly integrated with the airframe and flight
software. The products of this research effort allow NCDOT personnel to
compare airframes and payloads, to estimate UAS operational costs, to plan and
conduct regulatory compliant UAS flight operations, post-process data into
useful forms, and overall: to rapidly and properly scope the potential for
integrating UAS into wetland mapping efforts. In doing so, we deliver on the
overarching goal articulated in our research contract: to deliver
comprehensive, authoritative guidance and implementation strategies for
UAS-based remote sensing of wetlands.
