2.3 KiB
FEMTIC
FEMTIC is a 3-D magnetotelluric inversion code based on the following studies. FEMTIC was made using object-oriented programming with C++.
Y. Usui, 3-D inversion of magnetotelluric data using unstructured tetrahedral elements: applicability to data affected by topography, Geophys. J. Int., 202 (2): 828-849, https://doi.org/10.1093/gji/ggv186, 2015.
Y. Usui, Y. Ogawa, K. Aizawa, W. Kanda, T. Hashimoto, T. Koyama, Y. Yamaya and T. Kagiyama, Three-dimensional resistivity structure of Asama Volcano revealed by data-space magnetotelluric inversion using unstructured tetrahedral elements, Geophys. J. Int., 208 (3): 1359-1372, https://doi.org/10.1093/gji/ggw459, 2017.
Y. Usui, T. Kasaya, Y. Ogawa and H. Iwamoto, Marine magnetotelluric inversion with an unstructured tetrahedral mesh, Geophys. J. Int., 214(2): 952-974, https://doi.org/10.1093/gji/ggy171, 2018.
The website of FEMTIC: https://sites.google.com/view/yoshiyausui/femtic
Functional overview
FEMTIC gives a three-dimensional electrical resistivity structure from the response functions at observation points on the Earth's surface.
Mesh type: tetrahedral mesh, hexahedral brick mesh, and non-conforming deformed hexahedral mesh
Data type: impedance tensor, vertical magnetic transfer function, inter-station horizontal magnetic transfer function, phase tensor, apparent resistivity, and phase.
Parallel computation: Hybrid MPI/OpenMP parallel calculation can be used.
Model parameter: Subsurface electrical resistivity and distortion matrix of galvanic distortion.
Release note
v4.1 Nov. 9, 2021 This new version supports difference filter. The error calculation of log10(apparent resistivity) is modified. Rotation angles of distortion matrix are limited to from -90 to 90 (deg.) when gains and rotations of galvanic distortion are estimated.
v4.0 Jun. 3, 2021 This new version supports non-conforming deformed hexahedral mesh.
v3.5 Jan. 11, 2021 This new version supports observed data of apparent resistivity and phase and unsymmetric roughening matrix.
v3.4.7 Sep. 4, 2020 The integer indices into the multiple right-hand-side vectors and solution vectors were changed from 32-bit to 64-bit.
v3.4.6 Sep. 2, 2020 This version allows us to make resistivity of every individual subsurface element to be a different model parameter, in analogy with other 3-D inversion code.