April KEGS Talks
Details of the KEGS talk happening this month.
Title: Semi-Airborne EM is Transforming Resource Exploration
Speaker: Johannes Stoll, Mobile Geophysical Technologies GmbH
Date: Tuesday, April 14th at 4PM Eastern
Location: Online. Register for the virtual session below.
Abstract:
Airborne and ground electromagnetic methods have been utilized to explore for minerals, groundwater, and other extractable resources for more than six decades. Today, an unmanned aerial vehicle (UAV) configured with a lightweight EM sensor is deployed reducing both time and cost of the data collection. When a ground-based transmitter is utilized, the depth of exploration is increased along with resolution. The net result is a high-definition volumetric map of variations in the surface electrical conductivity. Advances in 3D numerical modeling, data analytics, combined with high-definition geophysical imaging data and AI-concepts have the potential to transform the exploration process from anomaly detection to defining, in significant detail, the geology and geological processes.
Semi-airborne electromagnetics (SAEM) employs a powerful, transmitter to inject electrical current into the subsurface. A drone configured with a lightweight EM receiver is deployed to autonomously map the secondary magnetic field within the area of investigation. SAEM successfully combines the greater depth of investigation achievable with ground-based EM methods with the increased speed of data collection characteristic of airborne geophysical mapping and the reduced per data point cost obtainable with UAVs. Moreover, the higher quality data along with increased spatial data density directly translates to improved, more accurate 3D models.
In this presentation I will show the results of a SAEM survey in a known porphyry copper mining area and a groundwater survey on a volcanic island. Finally, I will discuss concepts to use drone EM to establish 3D array Electromagnetics aiming to enhance the resolution of the subsurface.
Bio
Johannes B. Stoll, PhD., is the founder and CEO of Mobile Geophysical Technologies GmbH, a drone geophysical service company. Educated in physics and electrochemistry, during his 25 year career in exploration geophysics, he has held numerous positions in the Oil & Gas industry and research institutions.
profession.
Upcoming KEGS Talks
We are currently looking for speakers for our spring sessions. If you are interested, please reach out to any KEGS Executive.
KEGS Ottawa
Hi KEGS Ottawa
If you have suggestions for a presenter for May, please get back to me.
For those who wish to join our meeting remotely this month, the Teams meeting link can be found below.
Note: In order to enter Harrison Hall, you will have to show some Canadian identification: a passport, permanent resident card, driver license, or health card. If you are a foreign student and have a residency visa, that should work too. Send me an email if you are not Canadian and have some questions about whether your identification will work. The reason for this extra complication is that Harrison Hall is inside the controlled area. Checking everyone's id documents might take time - please try to get on site with some time to spare for the extra security procedure.
April Presentation
Date: Wednesday April 15 at 4:30pm
Location: GSC, Harrison Hall, Room 177, 601 Booth St., Ottawa
Title: “Improved Workflow for UAV-Gamma Ray Spectrometry: A 3D Spatial Inversion Approach”
Speaker: Neeraj Nainwal, Queens University
Bio: Neeraj Nainwal is a final-year PhD candidate at Queen’s University, Canada, supervised by Dr. Alexander Braun. His research focuses on improving UAV-borne radiometric survey workflows and combining radiometric and magnetic data using machine learning to improve mineral targeting. He completed his Master’s degree at the Indian Institute of Technology Kanpur in 2020, where he worked on groundwater contamination and transport modeling using electrical resistivity methods. He received his Bachelor’s degree in Geoscience Engineering from the University of Petroleum & Energy Studies, India, in 2017. He also has over a year of experience working in the oil and gas industry before returning to academia. His main interests include numerical modeling, inverse theory, and improving survey design to make geophysical studies more efficient and cost-effective. Besides his PhD, he provides consulting support for UAVborne radiometric and magnetic surveys, focusing on optimized survey planning and data
processing. After completing his PhD, he plans to continue working in this area and develop practical solutions to reduce uncertainty in field data.
Abstract: Advances in sensor miniaturization and UAV platforms have made gamma-ray spectrometry (GRS) a practical tool for high-resolution radiometric mapping. Unlike traditional helicopter surveys that use large detectors at higher altitudes, UAV surveys operate much closer to the ground with smaller detector systems. This enables more detailed measurements but also makes the observations more sensitive to terrain variations, detector footprint, and the three-dimensional geometry between the source and detector. Most radiometric processing workflows still used today were designed for higher-altitude helicopter surveys and do not explicitly account for these effects. In this study, we evaluate a terrain-aware spatial inversion approach for processing UAV-borne GRS data and compare the results with conventional processing methods. The method accounts for survey geometry, terrain effects, and the overlap of detector footprints between neighbouring measurements. To examine how these factors influence the measurements, we performed a series of synthetic sensitivity tests using simulated survey conditions. We then applied the method to two UAV radiometric datasets collected in Madison County, Montana, and Arizona. The synthetic experiments show that terrain geometry can significantly influence measured gamma-ray signals and should not be ignored during processing. Results from the field datasets indicate that conventional processing produces maps that generally follow the local geology but may contain artefacts related to footprint overlap and terrain effects. In contrast, the inversion approach produces more spatially continuous anomalies and reduces flight-line artefacts while remaining consistent with geological patterns. These results suggest that the proposed approach can improve the interpretation of modern low-altitude UAV-borne radiometric surveys Gorda Ridge.
Upcoming KEGS Ottawa Presentations
Microsoft Teams meeting
Join: https://teams.microsoft.com/meet/26683257569828?p=7wzY9JVZnO07cHOwjT
Meeting ID: 266 832 575 698 28
Passcode: i9Ln3bq2
KEGS Ottawa information
The KEGS Ottawa group meets on the 3rd Wednesday of each month, usually at the GSC on Booth St. It is also possible to hold the presentations at other venues in Ottawa. We generally follow our presentation by adjourning socially to a nearby local establishment.
Please contact Luise Sander, SGL, luise@sgl.com, (613) 521 9626 for:
- any upcoming KEGS Ottawa presentations
- if you know anyone who might be interested in presenting to our KEGS Ottawa group
- if you know anyone who should be included on the KEGS Ottawa email group
- if you are on the KEGS email group and would like to unsubscribe from it
Luise Sander
Self proclaimed KEGS Ottawa coordinator
PGO's 2026 Virtual Symposium
April 7, 9, 14, 16, 2026
12:00 p.m. to 1:30 p.m. ET
This four-session virtual event will bring together speakers from across the geoscience community to discuss topics shaping professional geoscience practice today.
Attention PGO Student Members!
This Symposium is free for you. To register, please email info@pgo.ca with your name, PGO student membership number, and the session(s) you wish to attend.
Early bird deadline is March 31, 2026. Register early!
Symposium Sessions
- April 7: Session A | Understanding the Role of a QP Under NI 43-101
- April 9: Session B | Beyond the Surface: Trends and Realities in Complaints
- April 14: Session C | Independent Professional Judgement in the Public Interest
- April 16: Session D | Strengthening the Geoscience Workforce Across Generations
Click on the link for more information: https://www.pgo.ca/events/2026-Annual-Symposium-Main
EMIW 2026
The 27th Workshop on Electromagnetic Induction in the Earth and Planetary Bodies will take place in St. John's, Canada, from 2nd to 8th August, 2026.
For information on St. John's and Newfoundland and Labrador go here and here.
The provisional schedule of important dates is:
Registration, abstract submission & financial support applications open ... 15th January.
Early-bird registration ends and financial support applications close ... 15th March.
Abstract submission closes ... 15th May.
These dates are subject to revision.
For more information, please visit the EMIW 2026 website
If you have any questions about the form contact me at walker@cwgeophysics.com
