Login to access member pages

CSIRO Modules

The Australian CSIRO has been developing Advanced EM modelling algorithms for approximately 25 years. Maxwell provides a user friendly interface from which to execute these algorithms for forward and inverse modelling.

Maxwell allows the user to define, display and edit model parameters through drag-and drop mouse operation. Layered earth, thin-sheet, prism and mesh models can be built in Maxwell’s 3-D visualisation environment.

  • Requires Maxwell version 5 or later.
  • Ground system configurations tested include drill-hole, fixed, coincident and in-loop systems and MT.
  • Airborne modules can model any frequency or time domain system. The transmitter is represented as a magnetic dipole for computational efficiency. Configurations tested include Geotem (dB/dt, B), VTEM, GTK/BGS wingtip, Tempest, Dighem, Spectrem, Aerotem and shipborne VCP broadside systems.
  • All inversion routines are based on the damped SVD decomposition method (as per Grendl).
  • CSIRO module.txt files are provided which provide full details on the model parameters.
CSIRO function matrix

 

Grendl

  • Layered earth forward and inverse modelling of DC apparent resistivity or ground TEM data, with square wave
  • Calculation of apparent resistivity
  • dB/dt or B field data
  • Limited to in-loop and coincident loop geometries

Beowulf
  • Layered earth for ground and borehole data
  • Forward and inverse modelling
  • Frequency and time domain

Airbeo
  • Layered earth for airborne EM data
  • Forward and inverse modelling
  • Frequency and time domain

Leroi
  • Multiple thin plates in basement below multiple
    layers
  • Ground, underground and borehole data
  • Forward and inverse modelling of frequency and time-domain data
  • Loop, groundeddipole, magnetic dipole or plane
    wave source

LeroiAir
  • Multiple thin plates in basement below multiple layers for airborne systems
  • Frequency or time domain
  • Forward and inverse modelling
  • Plates confined to basement

Marco
  • 3D rectangular prisms within multiple layers
  • Forward model only
  • Ground or borehole systems
  • Conductivity contrasts < 1:300
  • Much faster than Loki, more general than Leroi

MarcoAir
  • 3D rectangular prisms within multiple layers for airborne systems
  • Forward model only
  • Conductivity contrasts < 1:300
  • Much faster than Loki, more general than Leroi

Loki
  • 3D mesh /voxels based on compact finite edge elements with topography
  • Forward model only
  • Ground or borehole systems
  • Resistivity contrasts <1:100,000

LokiAir
  • 3D mesh/voxels based on compact finite-edge elements with topography for airborne systems
  • Forward model and inversion
  • Resistivity contrasts <1:100,000

Samaya
  • General 3D local mesh within a uniform host
  • Forward model only
  • Full ground and downhole modelling
  • Loop source, grounded dipoles, MT

SamAir
  • 3D prism containing 3D mesh within a uniform host
  • Forward model and inversion
  • Faster runtime than Loki for multiple sources

Arjuna
  • General 2D mesh with 3D sources
  • Forward modelling only of inductive sources and receivers
  • Finite loops lie on the surface
  • Accurate even for very high contrasts
  • Includes topography
  • Use where targets are effectively 2-D

ArjunAir
  • General 2D mesh with 3D sources for airborne systems (using a dipole source)
  • Forward and inverse modelling
  • Accurate even for very high contrasts
  • Includes topography
  • Use where targets are effectively 2-D
  • Any AEM system in time or frequency domain
  • Faster runtime than LokiAir