RESIX v3  1D Forward and Inverse
Modeling of DC Resistivity
General
RESIX is an interactive,
graphically oriented, forward and inverse modeling
program for interpreting resistivity sounding data in
terms of a layered earth (1D) model. Sounding curves
can be entered as a function of a for Wenner or
polepole soundings, AB/2 for Schlumberger soundings, R
for dipole soundings or N for dipoledipole or
poledipole soundings.
Sounding curve values are entered
as apparent resistivity as a function of spacing.
Forward modeling enables you to calculate a synthetic
resistivity sounding curve for a model with up to ten
plane layers. Resistivity sounding curves are calculated
using linear filters.
Shifting of data with overlapping
curve segments is handled automatically by shifting the
synthetic curve to match the offsets between segments in
the data. This is done by assuming the data for the
longest spacings is correct and shifting segments at
shorter spacings to meet the data at longer spacings.
Alternatively, you can shift the data curve itself to
meet either the longest or shortest spacing segment.
This can be done either automatically or manually in the
interactive graphics mode using the Shift Segments
option.
Masking of data is achieved in the
interactive graphics interpretation module by pointing
and clicking on data points. These points can be
unmasked or deleted according to the users needs. Masked
points do not influence the error or inversion
calculations. Interactive model input via the mouse
allows the user to see changes in the calculated curve
as he enters the model graphically. Graphic entities of
the plate output may also be resized and positioned
using the mouse.
Inverse modeling allows you to
obtain a model that best fits the data in a least
squares sense, using ridge regression to interactively
adjust the starting model parameters. You can constrain
some of the starting model parameters so the inversion
will not adjust them. Starting models for inversion can
have up to 8 layers. Forward models can have as many as
10 layers. Constants can be applied by fixing (or
freezing) a parameter, or by imposing limits on a
parameter. Parameters can be resistivity thickness of
layers, or resistivity/depth to bottom of layers.
Results from forward or inverse
modeling can be directed to a printer or plotter for
report ready, hardcopy output. Results can also be
saved in a binary random access disk file for later
retrieval. Inverse modeling can be carried out in an
unattended batch mode. Resix provides several options to
present the observed data, the theoretical (forward)
data, and the geoelectrical model section used to
calculate the forward response. This information can be
graphically presented individually on a dot matrix
printer, a laser printer, or a pen plotter. You can also
print the data and model section in a tabulated,
paginated form directly to a text printer.
Data stroage is handled by a new
data base file format that holds up to 200 data sets (or
sounding curves). This size of the file depends on the
number of sounding cureves it contains.
Standard Components
Resix v.3 software and instruction
manual.
