IGMAS+ is a software for 3-D modelling of potential fields and its derivatives under the condition of constraining data and independent information. It comes with tools for forward and inverse modelling. IGMAS+ has a long history starting 1988 and has seen continuous improvement since then with input by many contributors.

Since 2019, IGMAS+ is maintained and developed at The Helmholtz Centre Potsdam - GFZ German Research Centre for Geosciences by the staff of Section 4.5 – Basin Modelling and ID2 – eScience Centre with strong ongoing support by H.-J. Götze and S. Schmidt from CAU Kiel. The official webpage of IGMAS+ is available at https://www.gfz-potsdam.de/igmas/. Each major version of IGMAS+ will be assigned with a new DOI. Intermediate releases including changelog can be found at
https://git.gfz-potsdam.de/igmas/igmas-releases/-/releases/.

In IGMAS+ the analytical solution of the volume integral for the gravity and magnetic effect of a homogeneous body is based on the reduction of the three-folded integral to an integral over the bounding polyhedrons (in IGMAS polyhedrons are built by triangles). The original algorithm has been extended to cover all elements of the gravity and magnetic tensors as well. Optimized storage enables extreme fast inversion of material parameters and changes to the model geometry and this flexibility makes geometry changes easy. Immediately after each change, model geometry is updated and the field components are recalculated. Because of the triangular model structure, IGMAS+ can handle complex structures (multi Z surfaces) like the overhangs of salt domes very well. It handles remanent and induced magnetisation of geological bodies and was applied to the interpretation of borehole gravity and magnetics.

Modelling is constrained by structural input from independent data sources, such as seismic data, and is essential toward true integration of 3D thermal modelling or even Full Waveform Inversion. Geophysical investigations may cover huge areas of several thousand square kilometres but also models of Applied Geophysics at a meter scale. Due to the curvature of the Earth, the use of spherical geometries and calculations is necessary. IGMAS+ can be used for both flat (regional) and spherical models (global) in 3D.

List of changes for Release 1.3.8656

Fixed
• Custom projection using GeoTools (#22)
• Voxel density units (#74)
• Dark/light theme selector not working for the first start (#83)
• The size of windows for text input (#76)
• Consistent user experience for all ptaforms (#69)
• Build problem (#65)
• Bug with reading "calculated (measured) Geoid" from ".station" format (#38)
• Build problem (#59)
• Spherical calculation settings of "Max. Length" (#37)
• An error occured when section was defined with normal (0, -1) (#35)
• Bug when save project button is disabled while reaching recent items directory (#4)
• EPSG codes not appearing in projection lists (#28)
• Multiple cutter showed anomaly field in white (#36)
• Residual field is in mGal/km when the gradients are calculated in Eötvös (#36)
• Wrong factor for magnetic field calculation with mT (#29)
• Bug related to memory settings (#31)
• Image export
• WorldWind renderer
• Linux executables

Added
• GFZ branding in installer (#14)
• Calculation of body volume (#32)
• GeoTools gt-referencing projection (#78)
• New flatlaf design themes
• Integrate update check (#43)
• Notification about missing coordinate system when starting spherical approximation (#16)
• 2-D View icon to the toolbar
• Warning for the missing projection
• This changelog

Changed
• Migrated to latest JOGL bindings (#84)
• Name of the app after installation changed to IGMAS+ (#81)
• About window (#53)
• Switch from JSyntaxPane to RSyntaxTextArea (#71)
• Migrated to new truelicense version v4 (#56)
• Using "imported" instead of "measured" for Geoid for export/import (#41)
• Disabled SSL certificate validation for WorldWind tile server
• Viewboard logo - GFZ logo is used now (#14)
• Switched to latest jython 2.7.2b2
• Switched to java8 as minimum requirement
• Switched to the latest parsii library
• Swtiched to the latest proj4j library
• Updated main logo
• Updated installer
• Version numbers will now be generated following [major].[minor].[ci_pipeline_id]-[commit_hash]-[testing].

Removed
• toolbox3d dependency (#57)
• Geometry inversion from installer (#33)
• Unsupported cluster installer