TDRH Version 2 Package

Important

In the spring of 2023, a new TDEM OcTree code (TDRH v2) was compiled. The TDRH v2 code uses a universally right-handed coordinate system; as opposed to the modified left-handed coordinate system used by TDoctree v2. TDRH v2 is also capable of modeling the secondary field, which is useful when data are collected during the on-time (e.g. UTEM).

TDRH version 2 is a program library for carrying out forward modelling and inversion of time domain EM data over 3D structures. The contents of this manual are as follows:

• 1. Package overview
  • 1.1. Description
  • 1.2. Program Library Content
  • 1.3. Licensing
  • 1.4. Installing TDoctree
• 2. Background theory
  • 2.1. Fundamental Physics
  • 2.2. Octree Mesh
  • 2.3. Discretization of Operators
  • 2.4. Forward Problem
  • 2.5. Data
  • 2.6. Sensitivity
  • 2.7. Inverse Problem
  • 2.8. Sensitivity Weights
• 3. Elements
  • 3.1. Program Library
  • 3.2. Main Input Files
  • 3.3. Supporting Files
• 4. Running the programs
  • 4.1. Contents
• 5. Examples
  • 5.1. Create octree mesh
  • 5.2. Create octree model
  • 5.3. Forward modeling
  • 5.4. Inversion
• 6. References