Since the original unmanned, radio-controlled vehicle created by Nikola Tesla in 1898, humanity has been fascinated with wireless, remotely-controlled instruments. Once society moved past the weaponization of this technology and opened the arena to commercial development, Unmanned Aircraft Vehicle (UAV) technology (or Unmanned Aerial Systems-UAS) has developed exponentially.
Why are Drone Surveys popular?
The advantages to UAV surveys are:
Flown by a pilot at a ground control station, autonomously on a pre-programmed flight plan or using a more complex automated system resulting in increased safety and precision
Relatively low costs regarding purchasing and maintenance when compared to fixed wing and helicopter surveys
Less noise impact on local wildlife when compared to other low-flying surveys
Currently, most effective over small areas (up to 20 square km - ~8 square miles)
The disadvantages to UAV surveys are:
Greater sensitivity to local weather systems and micro-climates (mountain cirque and glacier winds)
Poor to non-existent collision avoidance
Lack of standards for safe and consistent performance
Shorter flight times when compared to conventional aerial surveys
What can Drone Surveys do?
The migration of large, fixed wing UAV systems into smaller, multi-rotor UAVs is making its way for use in detailed aerial photographs, geophysical surveys and multi-spectral imagery.
Detailed Aerial Photography
Resolutions in the centimetre- to millimetre-range have been used to collect 2D and 3D data for high-resolution topography and structure mapping. A recently published multi-rotor UAV survey captured and compiled a DEM grid with a vertical resolution of 0.065 metres and an orthophoto with a spatial resolution of 0.0016 metres within an area ~700 metres long by ~ 180 metres wide and at a height of 60 metres (Gao et al., 2017). The data collected was used to study active tectonic processes for interpretations and measurements of faults.
Geophysical Surveys
With the development of more robust multi-rotor UAVs and the miniaturization of geophysical survey equipment, geophysical surveys via UAV are becoming more prominent. A low-altitude (5 metre height), magnetic survey was conducted within rugged terrain at a scale of 1:10,000 and 1:5,000 ( profile spacing of 100 and 50 metres) in Eastern Siberia and was suggested to replace the daunting physical task of ground magnetic surveys (Parshin et al., 2018).
Multi-Spectral Imagery
Multi-spectral and hyper-spectral satellite imagery has made its way into mineral exploration for use in mineral identification, alteration (clay and iron-oxide) mapping as well as supervised classification of lithological units. This technology typically requires bare-earth exposure in the form of vegetation-free zones (bedrock or soil), core samples, hand specimens or disaggregated samples (soil horizons). A multi-rotor UAV equipped with a hyper-spectral camera was used to identify multi-temporal fluctuations of acid mine drainage (AMD) iron minerals (Jaskisch et al., 2018).
What to look for in a drone survey?
A UAV survey will have the same requirements for filing expenses on your claim as other surveys. Make sure your deliverables include:
A spatial resolution that matches your area of interest
A report including methodology, vehicle parameters, flight times and instrument specifications
Mosaic/stitched final version of the data
To-scale map(s) of the results
Happy Droning!
About the Author:
Diana has over 20 years of experience working in the mineral exploration industry searching for diamonds and metals in a range of roles: from heavy minerals lab technician to till sampler, rig geologist, project manager and business owner. Following a Master of Science degree in diamond indicator mineral geochemistry, Diana has conducted field work in BC, NWT, YT, ON (Canada) and in Greenland. She has also been involved, remotely through a BC-based office, on mineral exploration projects located in South America, Africa, Eurasia, and the Middle East. Diana finished a Ph.D. at UNBC in 2017 researching geochemical multivariate statistical analysis and interpretation. Currently, Diana is the owner of Takom Exploration Ltd., a small geological and environmental consulting firm focused on metal exploration in BC and the Yukon.