Near-field FDEM Surface Anomaly

Electromagnetics
1

Greeting SIMPEG community,

My name is Michael Faran and I am very excited to use the software.
I am attempting to solve a certain problem I am currently facing, related to a FDEM 2D problem, similar to the link.
I want to show that SimPeg has potential for simulating forward EM fields correctly. The geometry of interest is a grazing angle Hz propagating along a boundary between air and homogenous half-space of water. I consider two horizontal loops of AC current above homogenous half-space of water. One is Tx and the other is Rx. I am trying to get the solution of decay by 1/ R^5 very far from the Tx Coil, as appearing in the paper
Nevertheless, when I activate my code I get a 1/ R^3 signal very far from the TX coil, and I do not understand what I am doing wrong.
I used a total magnetic field Tx and Rx FDEM simulation instead of secondary magnetic field, but it does not seem to alter the result
I wanted to attach my .py code, but I couldn’t.
Did anyone encountered this problem before?
Any ideas?

any help would be much appreciated,
Thanks,
Michael

2

Problem solved, I should have used the PointMagneticFluxDensity FDEM module instead of the PointMagneticField for the receivers. I do get a R^5 decay. I also fixed some data display issues of the magnetic fields that were in the original example given in the website regarding the image and real parts. See the attached file.

Michael
plot_inv_fdem_loop_loop_2Dinversion_for_Homogoneous_ground.py (13.4 KB)