ModEM Documentation

Welcome to the ModEM’s documentation! ModEM is a modular system for inversion of electromagnetic geophysical data.

ModEM was designed as a flexible electromagnetic modeling and inversion system, written in Fortran 95. Although the code can be (and has been) extended for inversion of more general types of EM data (e.g., controlled source, DC; see Meqbel and Ritter, 2015), the User’s Guide below explains the core system developed for 2D and 3D magnetotelluric (MT) problems.

While a primary design goal of the system was to allow simplified extension with regard to data types, modeling codes, parameterization and regularization, and inversion search algorithms (see Egbert and Kelbert, 2012; Kelbert et al. 2014). The stable MT program has a command-line interface, which controls available program options, and specifies required and optional input and output files.

User’s Guide

This documentation contains information about compiling, running and using ModEM, including information about the file formats, options for forward modeling, options for inversion, etc.

Contents:

• Obtaining ModEM
• Getting Started
  • Directory Structure
  • Compiling ModEM
  • ModEM Dependencies
  • Creating Makefiles from configure
  • Compiling
  • Running ModEM: The basics
  • Using Docker to Compile and Run ModEM
• File Formats
  • Data Files
  • Model Files
  • Model Covariance Files
• Forward Modeling and Inversion Options
  • Forward Modeling
  • Inversion
  • Inversion Ouptuts
  • Apply Model Covariance
• Beyond the Basics
  • Restart the Inversion
  • Nested Modeling
  • Flexible Air Layers
  • LOG10 Resistivity Model File Option
  • New Unit Testing Features for Code Developers
• Installing ModEM Dependencies
  • Installing MPI
  • Installing LAPACK and BLAS
• Contributing
  • Steps To Open a Pull Request (PR)
  • Tips & Testing
  • Building this Documentation
• Change Log
  • Release 1.2.0 - April 12, 2019
• Citations

CSEM Version of ModEM

Warning

The CSEM version of ModEM is not fully validated and has only been used in some instances. We cannot guarantee correct or accurate results with it.

For more information see csem_modem.

Spherical Version of ModEM

Warning

The Spherical Version of ModEM is not yet fully developed and we cannot guarantee correct or accurate results!

Support

Support for ModEM may be limited at times due to resources or developer availability. If you have issues, questions or encounter a bug, please open a GitHub Issue at: https://github.com/magnetotellurics/ModEM/issues/new.