1D Layered Model Resistivity Forward Modeling for Magnetotelluric (MT) Sounding

Magnetotelluric (MT) sounding is a geophysical method that utilizes natural electromagnetic fields to investigate subsurface electrical structures. The 1D layered model assumes subsurface media consist of horizontally stratified homogeneous resistivity layers, suitable for approximating simple geological formations.

The core of forward modeling lies in solving electromagnetic wave propagation responses through layered media at different frequencies. High-frequency electromagnetic waves primarily reflect shallow resistivity characteristics, while low-frequency components penetrate deeper formations. By calculating apparent resistivity and phase corresponding to each frequency, we can construct curves representing resistivity variations with depth.

Key implementation aspects include: solving electromagnetic wave propagation equations in layered media, impedance tensor computation, and deriving subsurface electrical parameters from surface observation data. This forward modeling approach provides theoretical response references for subsequent inversion interpretation, serving as a fundamental component in MT data processing. Code implementation typically involves recursive algorithms for layer propagation matrix calculations, using functions like impedance boundary condition handling and frequency-domain electromagnetic field solutions to simulate MT responses accurately.