BCGS Technical Talk – October 29, 2020
Speaker 1: Ron Bell, Senior Geophysicist & geoDRONEologist;
International Geophysical Services, LLC
Title 1: An All to Brief Review of Drone Enabled Geophysics
Speaker 2: Callum Walker, Ph.D Candidate, Applied Geophysics;
Department of Geological Services & Geological Engineering
Queen’s University
Title 2: Characterization and Mitigation of Unmanned Aerial Vehicle Electromagnetic Interference for Geophysical Surveying
Date/Time: Thursday, October 29, 2020 @ 4:30pm PST
Location: Online Webinar
Abstract: & Bio
Ron Bell, Senior Geophysicist & geoDRONEologist; International Geophysical Services, LLC
Abstract:
An All to Brief Review of Drone Enabled Geophysics
My presentation will begin with brief review on utilizing drones for geophysical mapping as it stands today. It is much more than hanging a magnetometer from a quadcopter. I will then opine on the Drivers and Restrictors that impact the use of drones. Following this bit, I will share a few of the lessons learned during the past several years which will be followed by a few predictions about what we are likely to see emerge in the next few years. I will close out my presentation with a few observations about the business of drone enabled geophysics.
Bio:
Upon entering the realm of exploration geophysics soon after graduating with a BSc in Applied Physics from Michigan Technological University in 1976, Ron realized he had found a home in a very special place. The place where a science driven working life intersected with a young man’s desire for adventure. For the next 4 decades, he gained experience in all manner of geophysical techniques applied to resource exploration, environmental and engineering subsurface site characterization, and resource extraction monitoring. In 2014, he began another phase of what is best described as “an unconventional career” when he began learning about unmanned robotic aircraft and how best to upgrade geophysical mapping with a touch of automation. In 2016, after a bit of introspection, he realized that he had become the world’s first and currently only geoDRONEologist. (pronounced – “geo” – “DRONE” – “ologist”}. In consideration of the amount of time he has devoted to the geophysics business, he reckons he can rightfully take on the title of “Senior Geophysicist and geoDRONEologist”.
Abstract:
Callum Walker, PhD Candidate, Applied Geophysics, Department of Geological Sciences & Geological Engineering, Queen’s University
Characterization and Mitigation of Unmanned Aerial Vehicle Electromagnetic Interference for Geophysical Surveying
An important consideration when designing unmanned aerial vehicle (UAV) geophysical systems involves characterizing and mitigating the electromagnetic interference signals generated by the UAV platform. The multiple, high-frequency electromagnetic interference signals, generated by a UAVs motors, have the potential to compromise the data quality of both UAV-borne magnetic and electromagnetic surveys. In this study, the permanent and induced components of the electromagnetic interference signals generated by a UAV’s permanent magnet synchronous motors (PMSMs) were characterized using spectral analysis. A specific electromagnetic interference characterization methodology was applied using three different magnetometers with unique sensitivities and sampling frequencies. These magnetometers included a low sensitivity, vector, fluxgate magnetometer and two high-sensitivity, scalar, optically pumped magnetometers. The results of these laboratory experiments where then tested and confirmed in the field during a suite of aeromagnetic surveys using a sampling frequency up to 1000 Hz. The successful integration of a specific geophysical payload and UAV platform, into a UAV-borne geophysical system, will be a unique process that preserves the integrity of the gathered geophysical measurements. This process can be informed by: (1) characterizing the sources of magnetic and electromagnetic interference generated by the UAV platform, and (2) analyzing the spectral content (up to 500 Hz) of the sensed total magnetic field in real-time during surveying. Once the UAV’s electromagnetic interference signals have been characterized, this information can be used to inform the appropriate mitigation strategy for specific sensors and applications. Appropriate mitigation techniques can include magnetic compensation, spectral filtering, magnetic shielding and positioning the geophysical sensor at a distance from the UAV. Noise characterization and the application of the correct mitigation technique allow for each survey to be optimized, leading to the acquisition of higher quality geophysical observations. Overall, this approach enables target-focused surveys and aims to optimize flight endurance of these geophysical systems.
Webinar:
A recording of this webinar is available on Youtube.