KEGS Ottawa September Meeting


Tuesday, September 20th 
4:30 p.m.

Harrison Hall
Room 177 
601 Booth Street  


First Speaker: Tomas Naprstek, Laurentian University


Tomas Naprstek


A new method for interpolation focusing on linear features, with an aeromagnetic example

When data are interpolated to make a gridded image, thin linear features can result in “boudinage” or “string of beads” artifacts when the features are running at non-perpendicular angles to the traverse lines. We present a new interpolation method whose focus is generating grids without the artifacts usually associated with thin, linear features. Our method is based around a three-step iterative interpolation process of a Taylor series expansion, a trend direction analysis, and a “normalization” process. Synthetic data and field data examples show a significant improvement over standard bidirectional gridding and minimum curvature methods for interpolating thin, linear features at oblique angles to the flight lines.

Tomas Naprstek is a Ph.D. student working under Richard Smith on aeromagnetic interpolation and interpretation problems. He has a background in physics, and enjoys applying computational physics to work in geophysics and other related fields. 



Second Speaker: Maxim Ralchenko, Carleton University


Maxim operating Vital Alert’s Automated Noise Data Acquisition Unit (ANDAU)


Coupling of very low frequency electromagnetic signals to long man-made conductors

In electromagnetic (EM) methods in exploration geophysics, long conductors are either targets or cultural noise. Through-the-Earth (TTE) radio operates on the same physical principles and can be used to study the effects of such objects on EM survey systems. In TTE radio applications, the signal couples to the conductor, which increases the radios' range. We combine field work and a finite difference time-domain (FDTD) code to better understand the effect of such conductors on TTE radio communications, which can be extended to EM survey systems. This approach has been useful in investigating a variety of coupling scenarios, which includes underground and surface railways, as well as elevator shafts in multistory buildings.

Maxim Ralchenko completed his B.Sc. (Earth Sciences) at Carleton University in December 2013. He started an M.Sc. in January 2014 under the supervision of Prof. Claire Samson, also at Carleton University, and was fast-tracked to a Ph.D in May 2015. In collaboration with Vital Alert Communications, his present research focuses on modelling and optimizing through-the-Earth radio communications, which has a variety of potential safety applications in mines, tunnels, and public safety.