Phase 1 ESAs may be difficult in situations where Environmental professionals have limited access, due to either the size or condition of the subject property. In addition, finding historical aerials younger than several months old is not often possible.


Terraphase has cost effectively deployed unmanned aerial systems (UAS), aka “drones” in this situation. A UAS flight provides a high-resolution current “bird’s eye views” of the property as well as video footage, as the drone can be flown into areas over physical barriers to vehicular or pedestrian access, dense vegetation, wetlands and natural hazards. Fixed-wing drones can cover tens of thousands of acres in a matter of hours. Quad-copter drones can easily cover smaller areas and more adeptly navigate certain features. Using drone outputs of several thousand small overlapping geotagged images, application of photogrammetry permits the construction of both 2D and 3D maps, digital elevation models and georeferenced orthomosaics that are then used in our Geographic Information Systems (GIS) as geotagged imagery for report figures.

Launch site for fixed-wing drone flight over 20,000 acre site with rugged terrain in support of Phase I ESA

Orthomosaic and the Digital Surface Model(DSM) processing previews

Side by side comparison of stock imagery compared to high resolution drone imagery of a site showing well pads that were part of a groundwater investigation