Remote Sensing: Unmanned Air Vehicles (UAV)

Key Project Information

Purpose: Research and Development Effort
Method: Utilization of UAVs as platforms for aerial photography, photogrammetry, infrared imaging, aeromagnetics and other remote sensing methods
Location: Development: Montana City, MT Testing: Warm Springs, MT
Client: Dewhurst Group, LLC and the State of Montana, Department of Environmental Quality
End-User: Dewhurst Group, LLC
Dates: 2011 - Present
Client Reference: David LeMieux, w. 406.841.5244, State of Montana Bryan Stueve, w. 406.933.5300,

Project Summary

The Dewhurst Group (DG) is testing, comparing, and developing various remote sensing methods appropriate for deployment on small remotely controlled UAVs. UAVs consist of multi-rotor aircraft capable of obtaining precision data from heights ranging from approximately 1m to 1000m above the ground. Current instruments under development include: high-resolution cameras for photogrammetry and base-map construction, long wavelength infrared sensors to map surface heat and specialized magnetometers to perform aeromagnetic surveys. The project goal is to develop tools that complement ground-based geophysical and geochemical methods for exploration and development.

Statement of Work

The UAV program involves the application of cutting ( bleeding) edge technology. These platforms are easily deployed and can operate independently once airborne, taking off, flying between waypoints, and landing with minimal operator interaction. They are electrically powered. Flight time varies with altitude and payload but in general, can operate at heights of 200m for 15-30min with a 2kg load. DG’s testing indicates that aerial photography from UAVs exceeds the resolution that can be commercially obtained. Additionally, oblique imagery can be easily taken on site depending on requirements.

The long wavelength infrared (LWIR) thermal imager can obtain both still and video imagery (color and monochrome palettes) that is highly sensitive to ground heat. The LWIR, with a spectral band of 7.5 to 13.5 micrometers, has a detection range from 1.8m to nearly 1km. The LWIR has been designed with frame rates that permit the export and import of the sensor without the need for special export control licenses.

The magnetometer used within the UAV program has been designed and manufactured in consultation with the Russian Academy of Sciences, St. Petersburg Branch of the Institute for Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (SPb FIZMIRAN). Both magneto-resistors, manufactured by Honeywell, Inc. and proprietary low-frequency torsion balance sensors are being developed. The minimum target sensitivity is 0.5 to 2 nano-tesla. This sensitivity goal is challenging due to the small size of the UAV, monitoring motion and positional challenges, and on-board electromagnetic noises. However, it appears achievable.

Currently, DG has a fleet of four UAVs in various configurations, including both octocopters and quadcopters.