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Version 1.5 (c) 2014 by Markku Pirttijärvi.

FDEMINV is a computer program that can be used to model and to interpret geophysical frequency-domain electromagnetic (FDEM) soundings using a horizontally layered earth model. The 1-D model is defined by the resistivity and thickness of a fixed number of layers and magnetic susceptibility can be assigned for one of the layers. The source is either a vertical or horizontal magnetic dipole. The receiver measures the vertical and horizontal components of the secondary magnetic field. The response can defined in different ways as a function of increasing frequency at fixed loop spacing (frequency sounding) or increasing loop spacing at fixed frequency (geometric sounding). Parameter optimization, which is based on linearized inversion method, can be utilized in 1-D interpretations.

Screen dump of the the FDEMINV program

FDEMINV is a 32 bit application that can be run on MS Windows operating system with a graphics display of at least 1024x800 resolution. Memory requirements and processor speed and are not critical factors, since large data arrays are not used and the EM solution is quite fast to compute even on older computers. FDEMINV has a simple graphical user interface (GUI) that can be used to change the parameter values, to handle file input and output, and to visualize the EM response and the model. The user interface and the data visualization are based on the DISLIN graphics library (

Download the FDEMINV.ZIP package (1100 kB).

The FDEMINV program requires only the 32 bit executable file FDEMINV.EXE. The distribution file (FDEMINV.ZIP) also contains a short description file (_README.TXT), this user's manual (FDEMINV_MANU.PDF), few example model file (*.INP) and an example data file (EXAMPLE.DAT). To install the program, simply unzip the distribution files on your hard disk or USB stick and a new folder appears. For more information, please, see the user's manual.

User's guide (FDEMINV_MANU.PDF) (340 kB).

This version from Octover 2014 comes with many GUI changes and fixes HMD systems (coplanar and coaxial modes were interchanged!)

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