Interpex is a software company dedicated to the production of high quality software for the processing, interpretation and display of geophysical data.

 P.O. Box 839 • Golden • Colorado • 80402 • USA


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  • Designed for Windows 9x, NT and XP 
  • Protected with User Name and Registration Code
  • Supports most VLF formats
  • Map view of any component with contours and color fill
  • Profile view of one or more profiles
  • Depth section view of Hjelt currents
  • Contours and color fill on depth section
  • User added labels on any view
  • Documentation consists of a detailed Windows Help 

VLF Data Presentation and Processing Package

Designed for Windows 9x and NT  

Download the Software

IXVLF is the successor to EMIX VLF, our DOS based VLF data processing and presentation system.

New is the addition of user defined labels 

To evaluate this package, download  and install the software and run it with the demo data set. Be sure to open and peruse the HELP file. Contact Interpex with any questions.

Data Import – 

  • ABEM WADI files

  • IRIS Instruments VLF files

  • Scintrex basic and XYZ++ VLF files

  • Generic XYZ and flat ASCII files.

  • Copy/Paste from Excel to spreadsheet editors

  • EMIX VLF binary data files (.VLX)


Apart from displaying VLF data IXVLF provides the user with two data filters. The FRASER filter converts cross-overs of the correct polarity into peak responses by differencing successive values of the tilt-angle along the survey profile.

The HJELT filter profiles are obtained by using the linear fit theory to solve the integral equation for the current distribution, assumed to be located in a thin horizontal sheet of varying current density, situated everywhere at a depth equal to the distance between measurement stations.

IXVLF was designed to read inphase and quadrature VLF data from instruments and files into a grid based data set. Easy to use editors allows for keyboard entry of data collected on a non digital instrument or for the editing of recorded data. Data sets are then saved in a binary file for quick and easy retrieval.

IXVLF has no restriction on the number of lines or number of stations allowed per line. Having said that, the spreadsheets are presently limited to 1000 stations, but this can be changed.

IXVLF™ Data Editing Spreadsheet.

The program allows for the export of VLF data into XYZ ASCII files.

The main feature of IXVLF is the interactive graphics viewing screens. The first option is the single map view that allows the user to view a contour map of any of the following datasets/components:

  • Magnetic field data
  • Fraser filter data
  • Hjelt filter data
  • Tilt Angle
  • Ellipticity
  • Field strength
  • In-phase component
  • Quadrature Component
  • Amplitude
  • Phase
  • IXVLF™ Map view display dialog.

    The map can be customized to show various fields/components, and to control color fill, contour fill, stacked profiles and colorizing stations and contours.

    Clicking on a line will toggle its display on the profile plot.

    When stations are displayed, clicking on a station will display the line containing that station on the profile display

    One, several or all profiles can be displayed on the profile display

    Right-clicking on a station will display the line containing that station as a Hjelt depth section. 

    Hjelt depth section window with color fill and contours

    The Hjelt depth section has a separate control for manipulating the display:

    A separate dialog controls the display of the Hjelt Depth Section

    Right-clicking allows for creating labels. Labels can be moved, resized and the text can be edited. Also, an arrow can be drawn or not. 

    Labels can be created by right-clicking on any graph. They can be displayed with or without an arrow.


    Copyright 2018 Interpex Limited. All Rights Reserved