Документ взят из кэша поисковой машины. Адрес оригинального документа : http://geophys.geol.msu.ru/STUDY/manual/ip1dmine.doc Дата изменения: Mon Oct 30 17:26:49 2000 Дата индексирования: Mon Oct 1 20:16:54 2012 Кодировка:

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119899, Russia, Moscow, Moscow State University,

Geological Faculty, Department of Geophysics,

tel. & fax: (7-095) 939-49-63,

E-mail: Sh@geophys.geol.msu.ru

WEB site: www.geol.msu.ru/deps/geophys/rec_labe.htm

A.A.Bobachev, I.N.Modin, E.V.Pervago, V.A.Shevnin
IPI-1D

Minimal (Free) programs for 1D VES data interpretation

We recommend to copy all programs and files to hard disk in IPI
directory, and create some separate subdirectory: DTG, DAT_RES and
PROGRAMS.
Notice: All programs are written on Borland-Pascal v.7.0, License N:
IA917A10020398.
CONTENT
0. About IPI Package 1
1. IPI-Gate 2
2. IPI-v.6.0 5
3. DVALL 9
References 10
IPI-1D programs for resistivity & Induced Polarization sounding
Interpretation appeared in 1990 for IBM-type PC. IPI-1D programs for VES
interpretation are used in more then 50 different geophysical organizations
in Russia and abroad (Hungary, Bulgaria, Vietnam, Mexico, Spain, Peru,
Egypt, Germany). IPI package consist of field data pre-processing program -
IPI-GATE; interpretational program - IPI (versions 6 or 7); program for
drawing apparent resistivity curves IPI-Curv; IPI-STAV program - for
statistical analysis VES data; IPI-Ekvi - for equivalence analyses of
interpretation model; IPI-RES2 - for preparing, drawing and printing
geoelectrical cross - section, IPI-Res - for preparing table of results.
IPI package is added by DVALL program for 1D forward VES calculations.
IPI_Plan works with VES data scattered in the area, not on one profile. IPI
programs may work in combination with IE2DL and IPI-2D packages of programs
for two-dimensional VES modeling and data processing.
About IPI-1D Package
1. IPI_GATE - program for pre-processing of VES field data. That means and
includes:
1) Calculations of geometric coefficients according to AO & MN
distances for AMN or AMNB arrays and calculations of (a.
2) Corrections of (a, if there are noticeable errors in data. These
corrections may be done with the help of "Mouse" or by editing values in
table, but in both cases with graphic control of the curve on the screen.
Corrections of the field curve are stored in special file for the case of
returning to initial non-corrected values.
3) Receiving of the united sounding curve from segmented one for
different MN values.
That process can be done by vertical shift of all segments to the definite
one (the first or the last) or by creating united curve without shifting.
More of that, all segments can be transformed to ideal MN/AB ratio, if in
some parts of curve this ratio is far from ideal.
Field data may be placed in Data - file in different forms: as Voltage
and Current values, as only Voltage values when current is the same for all
measurements, and as apparent resistivity values.
2. Some words about IPI interpretational program.
1.1. IPI program deals with VES or VES-IP in man-computer interactive
regime and draws theoretical and field curves on a display screen together
with ( (z) model curve.
1.2. IPI program works with group of sounding curves (from 1 to 100)
in one data file. All data in one file should be of the same type: only VES
or VES-IP. IPI may works with 5 different types of array: S - Schlumberger
(or half-Schlumberger), W - Wenner, D - Dipole axial, U - pole-pole two-
electrode array AM, L - array with linear current electrodes. For each
array program uses its own linear filter, calculated by authors.
The first step in interpretation - start model receiving. Looking at
the sounding curve the interpreter can suppose number of layers and
parameters values and create start model. Just after changing parameters it
is possible to calculate theoretical sounding curve and see the fit of it
with experimental one. Values of model parameters may be changed in table
or with the help of mouse right on the screen. When start model is
satisfied, it is possible to begin automatic minimization for achieving the
best fit between theoretical and experimental curves. Before automatic
minimization it is possible to fix up some parameters, which are a priory
well known.
In the case of IP sounding after interpretation of (a curve IP curve
is interpreted. At that stage ( values of layers stayed unchangeable
(fixed) as well as depths of resistivity boundaries. Values of IP
properties of layers and thicknesses of additional layers without
resistivity contrast may be changed.
When the interpretation of some or all VES's on profile is fulfilled
it is possible to see geoelectrical cross-section (with logarithmic or
linear scale along the depth axes).
Instruction to the program IPI_GATE
This program is used to prepare from (*.dtg) to (*.dat) file for IPI.
Initial field data may be placed in (*.dtg) file in different forms: 1) as
Voltage and Current values, 2) as only Voltage values, when current is the
same for all measurements, and 3) as Apparent Resistivity ((a) values.
The preparation process includes:
[pic]
Fig.1. Working window for IPI-Gate program
1. Calculation of Array geometric coefficients, according to AB/2 (or
AO) & MN distances (for Schlumberger or half-Schlumberger arrays only), and
calculation (a - values from values dV; (or dV and I), depending the type
of instrument (for stabilized or non stabilized current), for different
types of segments overlap.
2. Corrections of (a, if there are noticeable errors in data. These
corrections can be done with the help of "Mouse" or by editing values in
table, but in both cases with graphic control of VES curve on the screen.
Corrections of the field curve are stored in special file (*.dtn) for the
case of returning to initial non-corrected values (which are stored in file
*.dtg ).
3. Receiving of united sounding curve from segmented curve for
different MN values. That process can be done 1) by vertical shift of all
segments to the definite one (the first, intermediate or the last) or 2) by
creating united curve without shifting. More of that, 3) all segments may
be transformed to ideal MN/AB ratio, if in some parts of curve this ratio
is far from ideal (MN/AB is equal or more than 1/3).
4. Calculated and united (a data are stored in file *.dat for IPI and
other programs from IPI-1D package.
5. Calculated from dV (or dV & I) (a data are stored as segmented
sounding curve in file (*.rok) only for control calculations.
Input file for IPI_GATE should be with extension *.dtg.
Its structure:
1-st & 2-nd lines: any information about file (Profile, place, date,
description, name, etc.).
3-rd line: n_VES, IP_key, nABmax, n_segm (with sign), Type of array (with
sign), Key of Array (with or without mark "_").
3.1. n_VES - number of VES (no more than 100),
3.2. IP_key - key of IP (0 correspondents to VES, 1 - IP-VES), for IP-VES
it doesn't work.
3.3. nABmax - maximum distances Ab/2 in this file (no more than 30),
3.4. n_segm - number of segments in VES curves - 1. (Number of segments is
equal to number of MN lines menus 1). n_segm may be equal to 0,1,2,3,4. If
you use sign (+) (or nothing) before Number of segments, - all segments
will be moved to the largest MN, & when sign (-) - the moving to the
smallest MN is used.
3.5. Type of array (0,3,4). If you use (a values, Type of array = 0, if dV
(& I) Key = 3 or 4. 3 - for half-Schlumberger (AMN), 4 - for Schlumberger
(AMNB).
If you use sign (+) (or nothing) before Type of array, that means
input of dV and I, sign (-) means usage only dV, current value used only
once in file. When dV & I values are in mV & mA, (a in Ohm.m. When dV is in
Volts and I is in mA, (a is in kOhm.m.
3.6. Key of Array (S,W,D,U; S-Schlumberger array, W-Wenner, D-Dipole
axial, U-pole-pole AM array). When Key of array has mark "_", that means,
that overlap consisted from only one AO distance, not two as usual (see
fig.2,b and example 5 for *.dtg file).
4-th line: Ordering number of distance AB/2, from which the next segment
begins. For several segments will be several numbers.
5-th line: length (or -s) of MN line (or lines).
6-th line: set of distances AB/2 or AO.
A. If Type of Array is = 0, then:
[pic]
Fig.2. The order of data in VES segments
7 line: Name of VES (from 1 to 8 symbols)
8 line: number of distances for this VES.
9 line: (a values.
Footnote. In the place of two segments meeting (overlap), the order of
values dU, I or (a in correspondent *.dtg file lines is such as: sMN, sAO;
gMN, sAO; sMN, gAO; gMN, gAO, where s-smaller, g-greater (look at the
scheme). The standard for IPI-Gate two segments meeting consists of two AO
distances, and the last segment continues one point or more after the end
of two segments meeting (fig.2,a). There is possibility to work with
segments overlap in one AO distance (fig.2,b).
B-. If Type of Array is =-3 or -4, then:
7 line: One current value for the whole file
8 line: Name of VES (from 1 to 8 symbols)
9 line: number of distances for this VES.
10 line: dV values (in mV or V)
B+. If Type of Array is =+3 or +4, then:
7 line: Name of VES (from 1 to 8 symbols)
8 line: number of distances for this VES.
9 line: dV values (in mV or V)
10 line: I values (in mA or A)
Examples of *.dtg file:
Example 1 for stabilized current & AMN array
Bilibino-90, VES from 24.5 to 43.0. 1 & 2 lines - description of data
profile 4
1 0 17 1 -3 S {VES number, KeyIP, ?ax.nAB, number MN-1, ArrayType,
KeyArray}
9 {ordering number of distance for second MN}
1 10 { MN distances }
1.39 1.93 2.68 3.72 5.18 7.20 10.00 AB/2 values
13.90 19.30 26.80 37.20 51.80 72.00 100.00
139.0 193.0 268.0
10 {Stabilized current value - the only one for all VES}
26.5/4-n {Name of VES}
17 {nAB}- number of distances for this VES
3800 2150 1070 480 237 124 51 13.5 8.5 57 2.27 24 12 5.6 2.85 1.76 0.97
0.44 0.165 {dV values}

Example 2 for nonstabilized current & AMN array
1 & 2 lines
2 0 17 1 3 S {Num. of VES, KeyIP, max.nAB, number MN-1,
ArrayType, KeyArray}
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
58.0/3-n {Name of VES}
15 {NAB} - number of distances for this VES
980 940 720 480 400 385 183 138 72 26.5 300 26 110 178 20 3 2.7 {
Dv }
3.1 3.5 4.4 4.5 5.4 7.1 5.5 6.2 5.8 7.3 7.3 22.5 7.9 49 44 32 62 {
I }

Example 3 for (a
1 & 2 lines.
25 0 17 1 0 S {Number of VES, KeyIP, max. NAB, number MN-1,
ArrayType, Key of Array}
9 {number of the distance for second MN}
1 10 {MN distances}
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
0.5/4-s { Name of VES}
15 { number of distances for this VES}
1.59 1.49 1.39 1.67 1.67 1.30 0.66 0.49 0.58 0.46 {(a values
0.68 0.57 0.66 0.77 1.02 1.05 1.01 0.77 0.90 {in kOhm.m}

Example 4 for stabilized current & AMN array with 1 MN
Bilibino-90, VES: 24.5 - 43.0 { 1 & 2 lines - description of data
profile 4
1 0 17 0 -3 {Num. of VES points, KeyIP, max. nAB, num. of gates}
9 {number of the distance for second MN}
1 {MN distance}
1.39 1.93 2.68 3.72 5.18 7.20 10.00
13.90 19.30 26.80 37.20 51.80 72.00 100.00
139.00 193.00 268.00 {AB/2}
10 { Stabilized current value - one for all VES}
26.5/4-n { Name of VES}
17 { number of distances for this VES}
3800 2150 1070 480 237 124 51 13.5 8.5 5.7 2.27 1.2 0.56 0.285
0.176 0.097 0.044 { dV values}

Example 5 - {for one point overlap }
Pastuhovka, Lime street
Profile 5
1 0 12 +1 -3 _S { Num VES, KeyIP, max.nAB, num.of gates,
ArrayType, KeyArray}
8 { num. of first gate spacing }
0.95 10.0 { MNi }
1.39 1.93 2.67 3.72 5 7.2 10 13.9 20 30 40 50 { AO
distances }
100.00 { current value in mA }
40 { VES name }
11
310.000 155.000 70.000 35.000 21.000
10.000 4.000 1.650 15.000 9.400 4.800 3.100
Operations with the program
Program runs by pressing Enter when Bar is on the program name or by
typing IPI_gate.exe in command line.
You may run the program with option /M to transform VES curve to ideal
MN/AB ratio (MN=0).
You may run the program with option /n, n=0,1,2,3,4
If n=1 or 2 then first or second segment stayed fixed and other
segments moved to it.
If n=0 then united curve created without moving of any segments.
Examples:
IPI_GATE.EXE - conventional run of program.
IPI_GATE.EXE /M /0 - run with transforming VES curve to ideal MN/AB and
without moving segments.
IPI_GATE.EXE /M /1 - run with transforming VES curve to ideal MN/AB and
with moving all segments to the first segment.
IPI_GATE.EXE /2 - run with moving all segments to the second segment.
After its running the program shows all files *.dtg. You should select
field data. After pressing Enter you can see on the screen VES curve and
table with (a values. This is beginning the stage of field data correction.
If mouse is absent, you can correct values in table with the help of
keyboard. On the curve you select the point to correct, change old value to
new and press Enter. At that moment one can see changing on the curve.
If you have a mouse, its arrow on the screen is moving to the point to
correct, by pressing left button you catch the point and began to move it
into new position. New location is fixed by releasing the button. When
mouse is active one may use keyboard after pressing F8. Another pressing F8
returns you to mouse mode.
When correction is finished one may transform segmented curve into
united form by pressing Space or Right button of mouse.
Pressing "right arrow" you are moving to the right along profile.

IPI - program
for automatic interpretation of VES & IP-VES
1.1. IPI program deals with VES or VES-IP in man-computer interactive
regime and draws theoretical and field curves on a display screen together
with ( (z) model curve.
1.2. IPI program works with group of sounding curves (up to 100) in
one data file. All data in one file should be of the same type: only VES or
VES-IP. IPI may works with 5 different types of array: S (or Q) -
Schlumberger, W - Wenner, D - Dipole axial, U - pole-pole two-electrode
array AM, L - array with linear current electrodes. For each array program
uses its own linear filter.
1.3. IPI program may work with text Data file (that is in ASCII codes)
in any directory.
2. Files description of IPI program.
2.1. Data VES or IP-VES should be written in text (ASCII) files. It
may be done with the help of many ASCII text-editors.
2.1.1. As a rule one file contain one profile of VES curves with VES's
quantity up to 100. For VES's this file may be created by IPI_Gate program
or manually. For IP-VES it may be done only manually.
Every data file should satisfy to the next demands:
1. It may contain from 1 to 100 VES's.
2. All data in file should be of the same type: VES or IP_VES.
3. All VES curves should be with the same set of AB distances and
should begin with the same
AB value. But total quantity of distances may be different.
4. All curves should be united (not segmented). For operation with
segmented curves see
IPI_Gate instruction.
2.1.2. Results of interpretation contain in file (*.RES) (only one
resulting model for one VES location). These models may be used as starting
models in reinterpretation process.
2.1.3. All files for one data set (profile) have the same name, but
different extensions:
*.DAT - for initial data,
*.RES - for start models and results of interpretation.
2.2. Initial Data-file structure.
Data-file should have *.DAT extension and definite structure. Format
of data in each line except 5-th may be arbitrary.
1-st & 2-nd lines: any information about file (Profile, place, date,
description, name, etc.).
3-rd line: n_VES, IP_key, nABmax, Key_Array
3.1. n_VES - number of VES (no more than 100).
3.2. IP_key (0 correspondents to VES, 1 - VES-IP respectively).
3.3. nABmax - maximum number of distances AB/2 in this file (no more than
30).
3.4. Key_Array - Key of array and filter type: S,Q - Schlumberger, W -
Wenner, D -Dipole axial, U - pole-pole two- electrode array AM, L - array
with linear current electrodes. For each array program uses its own linear
filter for direct VES problem calculation.
Note: Q-is used for fast filter (8 coefficients, 6 points / decade), S-
for exact filter (15 coefficients, 7 points/ decade). If Key_Array wasn't
written, the program used fast Schlumberger linear filter (Q). All filters
were calculated at Geophysical department of Moscow university, were tested
with help of exact theoretical curves with resistivity contrast up to 10000
(upward and downward) and its accuracy is better or at least no worse than
accuracy of all known foreign filters of the same length.
4-th line. AO or AB/2 or R=OO' (for Dipole Axial array) values. For Wenner
array IPI-1D programs use AB/2, but not AB/3 values.
5-th line. Name of VES location (beginning from 1-st column). This name may
contain figures, Latin letters and some other symbols (-),(_),(/). The
total length of name - no more than -10 symbols.
6-th line. nAB_VES, nAB_IP - number of AB/2 values for VES location,
separately! for (a and (a (IP) curves. These values should be equal or less
than nABmax (see 3-rd line). These would be less if some data for the last
several distances are absent. For VES mode nAB_IP may be absent.
7-th line. Apparent resistivity ((a) values for one VES location.
8-th line. Apparent chargeability ((a for IP) values for the same VES. If
KeyIp = 0, then this line is absent.
Lines from 5-th to 8-th should be repeated n_VES times for all VES's
without empty lines.
Example:
Profile VES
28.04.90
3 1 11 S {Num.of VES points, KeyIP, max.nAB, Key_Array}
1 1.3 1.9 2.7 3.2 5.2 7.2 10 13.0 19 27 {AB/2 distances}
1d {VES name}
11 11 {nAB_VES, nAB_IP}
25.00 25.00 32 40 50.00 60.00 70.00
75.00 70.00 60 50 {(a }
1.00 2.00 2.00 4.00 5.00 6 7
8.00 7.00 10.00 11.00 {(a }
2 {VES name}
11 11 {nAB_VES, nAB_IP}
20.00 25.00 30.00 40.00 50 60 70.00
72.00 70.00 45.00 30.00 {(a}
11.00 15.00 19.00 25 30 20.00 16.00
14.00 11.00 10.00 8.00 {(a }
3 {VES name}
11 {nAB_VES, nAB_IP}
22.00 25.00 30.00 40.00 50.00 60 70.0
72.00 70.00 50.00 45.00 {(a }
1.00 2.00 3 4.00 5.00 6.00 7.00
8.00 7.00 10.00 11.00 {(a }
3. Operations with the program.
3.1 To operate with the program one can use next keys: Enter, Esc,
functional keys (F1,.., F10), keys for cursor moving (arrows, PgUp, PgDn,
Home, End), and also Ctrl-N & Ctrl-Y (that is simultaneously pressed keys
Ctrl and corresponding letter). Key's function depend on the place in
program, where it is used.
Brief information about operation with program is in Menu, in left
lower part of the screen. Pressing F1 (Help) one can receive more
information about keys function.
|Selection file |Interpretat|Cross-sect|Exit |
|name |ion |ion | |


Running IPI program leads the user to the MAIN MENU:
The first step in operation with the program - is selection file name.
On display screen the list of all *.DAT files appears. For selection one
should move bar on definite file name and press Enter. The program load all
VES curves from this file in memory. If file *.res for that *.dat exist,
The program also load models. If some error is found, then program
announces about it and finishes operation.
When Data-file is chosen, one can begin interpretation. If number of
VES's more than 2, it is possible firstly to draw apparent resistivity
pseudo cross-section and after that begin interpretation.

Stages of operation
3.3. The 1-st (main) stage is Interpretation. At this stage the
display screen is divided into 4 windows - the main (on the left upward)
and 3 additional - on the right and downward.
In the main window VES or IP_VES curves and also curves ((Z) or ((Z)
appear. In upper part of the window light yellow bar shows VES location on
profile and in Model menu regime yellow triangle shows model location, if
VES and model locations are not coincide. (See Model menu - 3.6).
In right upper window there is information about this VES on profile:
Name of VES, number of VES's rest (on the right of this point) and table
with either (a (or (a) values or model parameters. In right low window
there is the name of stage at the moment, and in left low window there is
Menu information.
Menu shows possible functions: automatic interpretation (Space or
Enter), Manual interpretation (F4), Models selection (F3), Additional
functions (Ctrl+), Help (F1), Return to Main Menu (F10), Drawing cross-
section (F5), Stage S, T and Dar-Zarrouk drawing (Ctrl+F8 or F8), changing
between IP-(a stages (F9) and vice versa.
Ctrl+F4 - corrections of (a of the field VES curve in table. As a
usual main corrections already have done in IPI-Gate program, but sometimes
additional corrections are needed.
When file *.Res is absent, initial (start) model for interpretation is
created automatically and consist of two layers. As a rule this model
isn't satisfactory, that is why you need to use the next stage - Selection
of initial model, that may be done in two ways: in Edit Model (F4) and
Model Menu (F3) regimes.
3.4. 2-nd stage: Selection of initial model in Edit Model (F4) regime.
Before interpretation one need to create or choose initial model. If
the model for this VES exists already in *.res file, this model is used as
initial one. If one begins to operate with data for the first time, then
models are absent and program creates two layer model to begin with.
Looking at the sounding curve the interpreter may suppose number of
layers and parameters values and type them in model table. To input in
model table, press F4.
To increase layers number - press Ctrl+N, to decrease - Ctrl+Y. To
change parameter value one may move cursor to definite table section, type
the value over old one and press Enter (or Up - Down arrows). Just after
changing parameters it is possible to calculate theoretical sounding curve
(F8), to see the fit of it with experimental one. Values of model
parameters may be changed in table or with the help of mouse, right on the
screen, if mouse is loaded. When start model is satisfied, it is possible
to begin automatic minimization (Space) for achieving the best fit between
theoretical and experimental curves. Before automatic minimization it is
possible to fix up some parameter values (F2), which are a priory well
known.
3.4.1. How to change parameter values?
There are two ways to change parameter values. The first way - is in
typing new value with keyboard and press Enter.
Another way to change parameter values consist of mouse usage. On the
((z) curve on the screen every linear segment corresponds to definite
model parameter (horizontal ones - to resistivity of layer and vertical -
to depth of boundaries). It is possible to select any parameter you need
either moving mouse indicator on that segment or moving cursor by arrow
keys in table. After selection one presses left mouse button or Ctrl+Enter.
Indicator on the screen transforms to light green line, horizontal for ( or
vertical for thickness (depth). This line one may move by mouse or cursor
arrows. You may see correspondent changes of parameter value in table. When
correction is finished, press right mouse key or Enter to save new value.
If Esc was pressed the previous value rests.
3.4.2. How to fix parameter value?
During interpretation it is helpful to fix some model parameters,
which are a priory well known.
For fixing parameter one should move cursor on it and press F2. Fixed
parameter becomes marked by light yellow color. To cancel fixing of
parameter - press F2 once more. In the process of automatic minimization
fixed parameters aren't changed. In IP mode interpretation all ( and Depth
values became fixed automatically. In this case only automatic changes in (
are possible.
But in IP mode ( and H values are allowed to change manually without
unfixing.
3.4.3. How to change layer's quantity?
To change layer's quantity one may divide any layer into two, or unite
two layers in one.
[pic]
Fig. 3. Division of one layer into two layers
[pic]
Fig.4. Uniting two layers into one layer
To divide layer one should move cursor on that parameter in table and
press Ctrl+N. In dividing process the upper new layer will have 0.4 part of
previous thickness, and the lower one - 0.6 part. Resistivity and
chargeability values of new layers will stay the same (fig.3).
If one want to divide the basement, then new layer will receive
thickness equal to 1.5 of sum all previous upper thicknesses. If dividing
layer has one its parameter fixed, after dividing corresponding new lower
parameter became fixed and upper - unfixed.
To unite two layers into one, you should move cursor on parameter of
the upper layer in table and press Ctrl+Y. Two layers will unite in one
with the thickness equal to sum of two thicknesses and resistivity equal to
DZ resistivity values of two previous layers (fig.4).
If one of two or both united layers have some its parameters fixed,
corresponding new layer parameter became fixed.
3.4.4. Forward problem decision - F8. After pressing F8 theoretical
VES curve becomes redrawn, and fitting error - a new.
3.4.5. Automatic minimization - Space or Enter.
3.4.6. Esc - return from Edit Model to Interpretation stage.
3.5. " Interpretation ".
3.5.1 When initial model is created, interpretational stage begins. On
that stage one may select one way among next ones:
F4 - manual interpretation stage (see 3.4).
F3 - stage of model selection, which helps to create initial model
automatically (F7) or select good fit model among models already existed
(F5).
Space or Enter - running automatic minimization.
Ctrl+F6 - create the table on the screen with apparent resistivity
values for experimental and theoretical curves, to see difference in %
between experimental and theoretical curves (press %) and then save this
table in file *.rkt (by pressing F2) and print it afterwards.
F8 (Ctrl+F8) - Calculate and show in table values of S & T for each
layer, or (after pressing Insert) - S & T totals. At that time Dar-Zarrouk
curve appears on the screen.
F9 - Passage from (a to IP interpretation and vice versa.
Ctrl+PrtScr - Printing hardcopy of the screen. (For Epson matrix
printer).
Left or Right arrow keys - finishing of interpretation at this
location and moving to the next (left or right) one.
F10 - Passage to main menu (to draw cross-section or exit).
F5 - drawing cross-section.
Next commands are used for moving along profile from one VES to another.
Esc - end of interpretation of given VES and moving to the next with
or without saving model. (After additional question - Esc - don't save,
Enter - save Last model).
Tab - change the direction of moving along profile on opposite one.
Right, left arrow - moving along profile at one step with redrawing of
VES curve and automatic saving of model without questions.
Ctrl + right (left) arrow - fast moving along profile without
redrawing of VES curves. To stop moving - press any key.
It is possible to move "around", pressing F5 - exit from
interpretation to Cross-section regime, pressing left or right arrow -
change position and pressing Enter - return to Interpretation at a new VES
position.
3.5.2. Automatic minimization ("Automate").
In the process of automatic minimization IPI program can be stopped, if:
1. number of iterations is more than 30.
2. all corrections to parameter values became too small.
3. Fitting error became smaller than 1%.
4. User pressed any key to stop minimization.
On the screen one can see lest square estimation of fitting error (in
%). This error is the estimation of fitting quality. For start model it may
be about 20-100%, and 1-10% after minimization, depending on errors and
noise in field data. For IP minimization should be done twice, first for (a
curve and after that for (a curve.
3.5.3. Stage S, T & Dar-Zarrouk (ST) (only in 6-th version).
Passage to that stage by pressing Ctrl+F8 or F8. Exit with Esc. In
table of parameters values of S & T of layers appear and after Insert
pressing these values change onto S & T total. On the screen Dar-Zarrouk
curve is drawing. DZ curve [R.Mailette (1949), E.Orellana (1963), A.Zohdy
(1978), I.Modin & V.Shevnin (1982), Electrical prospecting...(1994)] is
very informative representation of multi-layered model. With the help of DZ
you may estimate geological possibilities of electric sounding for definite
geological situation.
3.5.4. "Save model" - operation.
After finishing interpretation at a given point by pressing Esc, you
will receive a question: what model do you want to save? Either the last
model (Enter), or the best one (F3), or exit without saving model for this
location (Esc). That means, you received several models keeping temporarily
in memory and program asks what to do with them.
To avoid this question you may use right (left) arrow instead of Esc
at the end of interpretation. You will go to the next VES with automatic
saving of VES model without question.
3.6. "Model menu" (F3).
This stage helps create models or select models among models existed
already.
Right, left arrows. Looking of models for neighboring VES locations.
Yellow triangle shows position of model and Ч(Z) curve is drawing by dashed
line on the screen.
Enter - selection of seeing model as a start model for a given VES
point with calculation of the forward VES problem for this model (appeared
in the model table at the right side) and fitting error.
F2 - returning to model, existing before this stage.
F3 - returning to the best model for this location, which is keeping
in memory.
F5 - Automatic search of the best model among existed already by using
best-fit criterium for (a curves, according to mutual correlation function
maximum. When VES curve with model is very similar to a given one, its
model may be used as a start model for a given VES point.
F7 - Automatic estimation of initial model by transformation of VES
curve.
Esc - exit from Model menu to the stage of interpretation with keeping
of found model.
3.7 Stage of "Cross-section" (in Main Menu) is used to draw VES
results in the form of apparent resistivity cross-section, and to draw
results of interpretation in the form of geoelectrical cross-section, and
for printing results. To print cross-sections one should change color mode
into black and white mode. Also one may select the scale for cross-section:
linear or logarithmic. Apparent resistivity cross-section may be seen and
printed only in logarithmic scale.
5. The structure of model file - *.res.
This file should has extension *.res and definite structure. Format of
all lines except line 4 - arbitrary. This file may be written manually, but
the best way - to create it in the process of interpretation.
1-st & 2-nd lines. Description of profile rewritten from *.dat.
3-rd line. nMod - quantity of models in file. This value should be either
equal the quantity of VES's or less. In the last case the order of models
should be correspondent to the order of VES curves in *.Dat file.
4-th line. Name of VES (from the first column). It should be exactly the
same as that in *.dat file.
5-th line. nS, ErrRho_a, ErrEta_a.
Ns - number of layers in the model (from 2 up to 10).
ErrRho_a - fitting estimation for field and theoretical (a curves.
ErrEta_a - analogical estimation for IP curves. If KeyIp = 0, this
value is absent.
6-th line. Model resistivities for all layers.
7-th line. Model thicknesses.
8-th line. Model chargeabilities for all layers. (IP parameters). If KeyIp
= 0, this line is absent.
Lines 4-th - 8-th should be repeated nMod times for all models.
Example:
Test1
28.04.90
2
1d
3 7.1 0.0 {nLayers, Err_Rho_a, Err_Eta_a}
24.52 369.50 2.39 { ( }
1.65 2.80 { h }
0.1000 1.0000 0.1000 { ( }
3
2 10.0 5.0 { nLayers, Err_Rho_a, Err_Eta_a }
10.00 1.00 { ( }
1.00 { h }
0.1 2.0 { ( }
6. Calculation of forward VES problem.
6.1. For calculation of forward VES problem the linear filtering
algorithm with different filters for different arrays is used: Schlumberger
(Q,S), Wenner (W), Dipole-axial (D), pole - pole or two electrodes
potential array AM (U) and array with linear current electrodes (L) [3].
Selection of array type is realized by Key_Array (key of array) meaning in
3-rd line of data file. If Key_Array is absent or its symbol is wrong, than
"fast" filter (Q) for Schlumberger array will be used. Total length of VES
curve can't exceed 4 decades of logarithmic scale, that is corresponded to
VES distances from 1 m to 10 km, and total distances quantity shouldn't be
more than 30.
Result of calculation in VES mode is apparent resistivity ((a) curve,
and in IP_VES mode - that one and also apparent chargeability curve,
calculated according to G.O.Seigel - V.A.Komarov formula:
[pic]
[pic]
where j is from 1 up to nABmax, ra* - apparent resistivity value,
calculated in regard of chargeability, that is for model with resistivity
values (i where i from 1 up to nLayers and (i & (i - are the resistivity &
chargeability of layers:
7. Automatic minimization or inverse problem decision.
Inverse problem decision may be fulfilled by automatic or manual
correction of layers parameters.
7.1. Automatic minimization intends to minimize fitting or mean
squared error between field and theoretical VES curves. In VES mode it is
difference between (a values, in IP_VES mode - between (a firstly and then
between (a values.
7.2. For automatic minimization in 5 & 6 versions Zeydel algorithm is
used. It works very fast.
7.3. In VES mode minimization algorithm finds ( & thicknesses of
layers. In this process it is possible to use a priory information by
fixing well known parameters. Finding values in IP mode became possible
after finding ( & H values. In this case ( & H values became fixed and
process finds only 's.

INSTRUCTION TO PROGRAM DVALL
Program calculates VES curves with the help of linear filters.
In this program several filters, received by different authors, are
used: for Schlumberger, Wenner, DAS, Pole-pole AM array, array with linear
current electrodes. Several filters for each array help to select the best
filter (if you know exact (a values).
VES curves may be calculated for different sets of AB/2 distances:
geometrical progressions with step from 3 to 10 points/decade or for
arbitrary list of distances.
Data are in file DVL.DAT, results in DVL.RES (vertical table AO- (a)
and DV_IPI.DAT (results for IPI program). For IPI it is necessary to change
in 3-rd line of the file word NVES to real VES number in this file.
After running program one should select type of array and filter in
menu. In this program the next filters are used:
1. S1-Schlumberger array, E.Abramova filter, 15 koef., 7 points / decade.
2. S2-Schlumberger array, D.P.Ghosh filter, 9 koef, 6 points/dec.
3. S3-Schlumberger array, O'Neil filter, 20 koef.
4. S4-Schlumberger array, O.Koefoed & Dirks, 15 koef.
5. S5-Schlumberger array, E.Abramova filter, 8 koef.
6. S6-Schlumberger array, V.Shevnin filter,15 koef., (S-16)
7. W1-Wenner array, D.P.Ghosh filter, 10 koef.
8. W2-Wenner array, O.Koefoed filter, 14 koef.
9. W3-Wenner array, V.Shevnin filter, 15 koef., (W-14)
10. D1-DOS array, D.P.Ghosh filter, 23 koef.
11. D2-DOS array, V.Shevnin filter, 20 koef., (D-16)
12. U1-Pole-pole array AM, E.Abramova filter, 20 koef.
13. U2-Pole-pole array AM, V.Shevnin filter, 30 koef.,(U-17)
14. L1-Linear electrodes array, E.Abramova filter,19 koef.
15. L2-Linear electrodes array, V.Shevnin filter,20 koef.,(L-7)
Structure of file DVL.DAT:
1. The first line: NR, KEYAB.
NR - number of AB/2 distances, KEYAB - Key of AB/2 selection. The second
line depend on KEYAB;
2. The second line: AB/2 set.
If KEYAB=0, than AB/2 includes the list of distances:
0.5 1 2 4 8 16 32 64 128 256 512 1024 ! 2-nd line, 12 values, AB/2 list.
If KEYAB=1, than 2-nd line consist of two values: RN and KTM, that is RN-
first AB/2 distance and KTM - number of points/decade.
It is possible to use KTM from 2 up to 14, better from 4 up to 10.
1.0 6 ! 2 line: RN, KTM
3. The 3-rd line - VES - information about VES (up to 10 symbols or
number)
4. The 4-th line - NS - layers number.
5. The 5-th line: Ч values for all layers.
6. The 6-th line: thicknesses values.
Lines 3-6 may be repeated any times for different models.
Example of file DVL.DAT:
3 19 1 Probe of DVALLN 1-st line: NR,NS,KEYAB,VES
1. 6 2-nd line: RN, KTM, if KEYAB=1
1. 9. 1 3-rd line: RHO
1. 9 4-th line: H (thicknesses)

References
1. Kolesnikov V.P. VES processing and interpretation with the help of
computers. Moscow, Nedra edition, 1981. (In Russian)
2. Koefoed O. Resistivity sounding measurements. Elsevier scientific
publishing company, Amsterdam-Oxford-New York, 1979.
3. Statistical interpretation of geophysical data. F.M.Goltsman -
editor. Leningrad, SGU edition, 1981. (In Russian)
4. Shevnin V.A. Using computers for education of electrical
prospecting. Izvestija VUZ'ov, Geologija and Razvedka, 1985, N 12, p.111-
114. (In Russian)
5. Electrical sounding of geological medium. Moscow university
edition, part 1, 1988, 170 pp., part 2, 1992, 200 pp. (In Russian)
6. T.B.Janovskaja, L.N.Porohova. Inverse problem in geophysics.
Leningrad., LGU edition, 1984. (In Russian)
7. Electrical prospecting by resistivity method. MSU edition, Moscow,
1994, 160 pp. (In Russian).