MALA CX User manual

MALÅ CX System
Operating Manual v. 2.3EM
19-001024

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Table of Contents
_________________________________________________
1Introduction 3
1.1 Unpacking and Inspection 4
1.2 Repacking and Shipping 4
1.3 MALÅ Geoscience Indemnity Clause 4
1.4 Important information regarding the use of this MALÅ GPR unit 4
2CX Start up 5
32D Project 12
43D Project 14
4.1 Creating a 3D Project 15
4.2 Migration settings and Images for 3D Projects 19
5Object-Mapper Project 21
6EM Option 23
6.1 Resulting signals/images 24
6.2 Sensitivity 25
7GPS Functionality 26
8File Manager 28
8.1 Transferring data 30
9System settings 31
10 Upgrade 36
11 Batteries and Power supply 37
12 High Frequency antennas 38
13 Technical Specifications CX unit 43
14 Technical specifications HF Antennas 44

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1 Introduction
__________________________________________________
Thank you for purchasing the MALÅ CX, the main unit for operating the
MALÅ High Frequency antennas, both with and without EM option. CX10
gives you a High Brightness type of screen, while CX11 is equipped with a
Trans-reflective screen for best performance in bright daylight. The MALÅ
CX has built-in software for both data collection and on-site interpretation,
tailored for high-frequency applications, as concrete investigations.
We at MALÅ Geoscience welcome comments from you concerning your
experiences in using this equipment, as well as your impressions of this
manual. Please take the time to read through the assembly instructions
carefully and address any questions or suggestions to the following:
Main Office:
MALÅ Geoscience AB
Skolgatan 11
S-930 70 Malå
Sweden
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
North & South America: China:
MALÅ Geoscience USA, Inc. MALÅ Geoscience
2040 Savage Rd, P.O. Box 80430 R.2604, Yuan Chen Xin BLDG
Charleston, SC 29416 No. 12 Yu Min Rd, Chao Yang Distr.
USA Beijing 100029, China
Phone: [phone] Phone: [phone]
Fax: [phone] Fax: [phone]
E-mail: [e-mail] E-mail: [e-mail]
Technical support issues can be sent to: [e-mail]
Information about the products from MALÅ Geoscience is also available on Internet:
http://www.malags.com

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1.1 Unpacking and Inspection
Great care should be taken when unpacking the equipment. Be sure to
check the contents against those shown on the packing list and inspect the
equipment for any loose parts or other damage. All packing material should
be preserved in the event of damage occurring during shipping. Any claims
for shipping damage should be filed with the carrier. Any claims for missing
equipment or parts should be filed with MALÅ Geoscience.
1.2 Repacking and Shipping
If the original packing materials are not available, the equipment should be
packed in at least 80 mm of absorbing material. Do not use shredded
fibers, paper wood, or wool, as these materials tend to get compacted
during shipping, thus permitting the instruments to move around inside the
package.
1.3 MALÅ Geoscience Indemnity Clause
Operators of MALÅ CX or other MALÅ GPR systems shall hold harmless,
defend, and indemnify MALÅ Geoscience from and against any and all
losses, liabilities, damages, injuries, claims, demands, costs and expenses
or claims including claims by third parties arising out of the use or
possession of the MALÅ GPR system.
1.4 Important information regarding the use of this
MALÅ GPR unit
According to the regulations stated in ETSI EN 302 066-1 (European
Telecommunication Standards Institute):
- The CX unit should not be left ON when leaving the system
unintended. It should always be turned OFF when not in use.
- The antennas should point towards the ground, walls etc. during
measurement and not towards the air.
- The antennas should be kept in close proximity to the media under
investigation.
See also Chapter 9 System Settings.

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2 CX Start up
__________________________________________________
Before starting up the MALÅ CX GPR system the following connections
must be made:
- The CX to the antenna, using the antenna cable. The antenna cable
should always be connected before the CX unit is powered on.
- The CX to the battery or other power source, using the battery cable.
See Chapter 11.
- The encoder wheel to the antenna.
When all connections have been made, the CX can be turned on. Pressing
the On/Off button at top right-hand corner activates the system. More
information on the High Frequency Antennas can be found in Chapter 12.
Note! The antennas should be ON for a while before measurement, to
warm-up. An appropriate time is approximately 10 minutes.
Once active, the CX is operated using a dual function turn-push button
(bottom right on the monitor) to control the settings. By turning the button
right or left, a selection from a specific menu can be highlighted. By
pushing the button, the selection is activated.
Power
Antenna cable
Encoder

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There is also possible for the operator to navigate and execute all functions
using the remote buttons on the antenna (Figure 12.5), the HF cart (Figure
12.2) and on the extension pole (Figure 12.6). By pressing either the black
or red button the operator moves in-between the individual menus on the
screen and activates the selection by pressing the two buttons at the same
time.
The following screen is shown at start-up of the CX and the work flow of the
3 different project types are also shown below:
2D Projects
General settings
Data collection
3D Projects
General settings
3D settings
Data collection
Evaluation
Object Mapper Projects
General settings
Data collection
OM settings
Evaluation(OBM)
End
New
New
End
End
Main menu

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As seen three different measurement modes are available for the CX
system; 2D, 3D and Object-Mapper Projects. All these project types are
explained in detail in the following chapters.
However, for all of these three options, general measurements settings are
done first of all and in quite a similar way, so when selecting one of the
options (2D, 3D or Object-Mapper) the following screen is seen, the
General Settings window:

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In this menu the options for changing Antenna, Material Type, Depth
Window, Zero Depth, Acquisition mode (Wheel / Time) and Point Interval
are found. If the Filters options in turned ON (done in the System Settings,
see Chapter 9) it also shows up here.
The trace and radargram view (right side of the screen) shows directly how
the signal looks like. Moving the antenna over a surface will change this
view of the wiggle trace and the gray scale background.
Using the turn-push button or the remote buttons, each setting to be
changed is chosen (high-lighted) and the button pressed to activate it.
Once this is done, the different options are displayed and can be changed
by turning and pushing the button. Examples are shown below for changing
the Antenna and Wheel options.

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The Depth window (seen at right) defines depth of the measurement; in
other words the total length of time the electromagnetic wave is
transmitted. Three predefined depths are available, shallow, medium and
deep. Choose the appropriate one by pressing the turn-and-push knob or
use the remote buttons. Note! The depth window is depending on the
velocity of the material.
The option Find zero depth
is used to define the surface
level of the measurements.
To do this, activate the option
and follow the instructions on
the screen. The antenna is
hold on the ground in the
same position as where you
will measure.
The Material type is chosen
accordingly to the medium the GPR
investigation is carried out in. The
CX system lists a number of different
types of material and is a guide for
the operator when estimating the
depth to targets visible in the
radargram.
It is important to choose the material type and by that velocity carefully as
this affects the velocity (the velocity of the electromagnetic radar wave),
which is used to calculate the depth of the measurement.
When the correct material type is
selected, the velocity can be
changed according to the limits, or
estimated with the Velocity Wizard.
It should be remembered that the
velocity of electromagnetic waves is
lower in wet materials than in dry.
After the material velocity has been selected, two buttons will appear on the
screen, OK to confirm and go back General Settings and Cancel to do a
new selection.

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After selection of material type or by choosing User-defined the option
Velocity Wizard can also be entered to obtain correct velocity for the
media. The requirement to use the Velocity Wizard (both for the migration
and hyperbola fitting function) is that a point object needs to be visible in
the radargram.
Note! When using a hyperbola the best estimation of the velocity is made
when the linear object is passed in 90 degrees.
When choosing the Velocity Wizard
the following screens are seen, giving
you the option to carry out a short
measurement, find an object and by
that a hyperbola, to migrate or use for
hyperbola fitting as tools to estimate
the velocity.
Press Start to start the measurement.
Using the Migration option
Migration is a tool used to get an accurate picture of the subsurface. It
involves repositioning of return signals to show where structures are
located rather than where signals was picked up.
Change the Velocity until the best migrated picture is obtained.
Migration OFF
Migration ON
Using the Hyperbola fitting
The theoretical hyperbola is moved over the screen by activating the X-pos and
Y-pos buttons and the angle of the legs are adjusted to the hyperbola on the
radargram screen by changing the Velocity.

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Note! If you select a velocity value outside selected materials range, the
material will be set to “User-Defined”
The option Acquisition mode (in the General Setting view) and Wheel is
changed depending on how the measurements are to be gathered; by time
or by distance. If distance is chosen the correct encoder is selected. The
standard MALÅ Geoscience wheels are found in the list.
Point interval (or time in seconds) gives the distance between the
measured traces in the radargram.
Note! For 3D and Object-Mapper projects only the wheel acquisition mode
is available. Point interval is fixed in 3D projects depending on the used
antenna.
For all project types (2D, 3D and Object-Mapper) the filename is given
automatically by the CX system. See also Chapter 8 File Manager.
Note! To turn off the unit once the work is completed, use the QUIT-button
and then the on/off switch on the unit. If the unit is switched off using only
on/off switch, the file system in the unit can be corrupted and all the data
lost.
After using the QUIT option in the program and the power has been turned
off by the software, the user need to power off the CX unit by pressing the
ON/OFF switch on the unit itself. To turn the unit on again, wait for 5-10
seconds before pressing the ON/OFF switch.

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3 2D Project
__________________________________________________
2D Projects are defined as measurement in single profiles as seen below:
This type of project can for instance be used to the investigate layer
thicknesses, as concrete floors, asphalt thicknesses on roads, ice thickness
etc.
When the measurement settings (in the General Settings window) are done
and is pressed the following screen is seen:
1: Radargram screen (the resulting picture)
2: Main menus.
1
2
3
4
Concrete bottom
Re-bars

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3: Battery Status Indicator
4: Information Line showing the material type, the connected antenna
type, measurement depth, memory space and acquisition mode.
By choosing Start pressing the
turn-push button, a radar
profile measurement can be
started immediately.
By pressing the
operator has the possibility to
save a screenshot image of
the radargram seen on the
screen.
Note! See Chapter 7 for
measurements with a GPS.
As each profile is completed, press STOP to finish the project. The data
can be moved from the CX to a PC for further interpretation work (see the
Section Transferring data). Files can be continued by pressing NewP (New
Profile). To start a new 2D project press Exit and then start from the main
menu again.
To improve the visualization of radar data on the screen the CX provides
the operator with different filter and contrast options. For each option the
turn-push button is rotated to increase or decrease the effect.
Applies a background removal filter.
Changes the contrast of the radargram.
Applies time gain on the measured traces. The
settings for this filter can be changed, see
System Settings, Chapter 9.
A FIR filter can also be applied on the data, see Chapter 9.
Also in the 2D measurement mode, migration is possible, when the profile
is stopped.

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4 3D Project
__________________________________________________
3D Project is a tool that makes the gathering and visualization of radar data
measured in two perpendicular directions easier, directly in the CX unit. A
typical application for which 3D Projects are effective is the mapping of re-
bars and joists in concrete. The 3D Project option in the CX will guide you
through all steps involved in the data collection to the final processed 2.5D
view of the investigated area. The measurement can be carried out using a
grid-mat, for fast and easy data collection (Fig 3.1).
Figure 3.1 Examples of 3D Project measurements with a grid-mat.
For best result the grid-mat and the investigation lines should be placed as
perpendicular to the searched object as possible. If no knowledge of the
direction of for instance a rebar net is available, it is advisable to carry out

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some test measurements prior the 3D Project. This can be done by 2-3
single parallel profiles giving an indication of how the objects are situated.
See Fig. 3.2.
Grid-mat Grid-mat
Figure 3.2 Three single profiles are measured, and indications of
objects are marked with red. The 3D Project is carried out with one
direction along the interesting objects and one direction perpendicular to
the objects.
4.1 Creating a 3D Project
When the option 3D Project is chose and the measurements settings are
made (Note! Point interval is fixed in 3D projects depending on the used
antenna), press to reach the 3D Project window. The CX
system automatically will give the project a name.
Here the parameters for the
grid is set, in terms of size and
lines spacing of the wanted
3D cube.
If pressing Use Standard
Carpet the size will be set to
0.80 x 0.8 m and 0.10 cm line
spacing as the size of the
standard MALÅ Geoscience
grid-mat.
Note! The Grid size should be evenly divisible by the Line spacing. This is
applied automatically by the CX system. In other words, if you change the

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line spacing, the grid size will also change to become the nearest divisible
value. The same applies the values of Grid size.
Press continue to reach the 3D Grid project layout screen to do a final
check of the project parameters:
Choosing Start activates the 3D Project. During data collection the two
buttons on the antenna or on the extension handle are used as remote
controls, for choosing the Next profile and Start profile.
The number in the blue rectangle
refers to the distance on the grid
carpet.
Place the antenna carefully over the
start position (the red triangle shows
the start point and direction), then
follow the step below:
1) Press the black button, wait for a beep, and release the black
button.
2) Start to measure, by moving the antenna along the line on the
carpet.
3) Continue the measurement until a beep is heard again. The CX
automatically ends the line.

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4) Press the red button (to change measurement line), and wait for a
beep.
5) Place the antenna in the start position of the next line and start
from step 1 again.
If black button is pressed after a profile is collected, the software assumes
that the operator want to re-measure the current profile. The option
can also be chosen to re-measure the previous lines.
When all lines in one direction are
measured, the CX system
automatically will change to the
second direction.
Once the last profile is filled, press the red button one more time, then
press the “Process“ button, to process and view the data. This will take
some minutes.
This screen (above on right) shows the result of the calculations made to
create vertical and horizontal slices of the measured volume. The vertical
slice is seen on the right (X- or Y- direction) and the Top View, the
horizontal slice, is seen on the left.
By choosing one of the sections and turning the turn-push button the
sections can be scrolled to look at data within the cube, from the sides or
the top.

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For explanation of the three function buttons: see next
section in this manual.
The options Angle, Aperture and Threshold are filter settings for the Top
View and stands for:
Angle –The space between the single lines of data is being filled with
the help of an interpolation scheme. This interpolation can be
performed in different directions the angle parameter determines this
direction, -45 –+45. A value of 0 indicates orthogonal interpolation, the
normal case. This filter should mainly be used when the target
directions are not parallel with any of the profile sets.
Aperture –When targets are not exactly horizontal, it helps a lot if one
can view a depth/time interval instead of an instant time slice. This
parameter determines the thickness of the merged time slices. It should
be altered in order to better follow a dipping target or to view several
targets, on different depths, in the same top view. When the parameter
is altered, the time/depth span is shown interactively on the side view.
Threshold –This is a composed filter. It mainly sets a threshold on the
top view data. If we go to the positive direction then levels below the
threshold is given some fixed negative value and levels above are
presented. If we go to the negative direction then levels above the
threshold is given some fixed positive value and levels below are
presented. The parameter is expressed in percent of maximum or
minimum amplitudes found the dataset.
When pressing one can toggle to a full screen of the Top View.
Here there is a possibility to save an image of the selected view as a result
of the investigation. These images will be saved with an automatic name.
The image format is chosen in the System setting, Chapter 9.
A circle can be turned ON and OFF and moved in the picture, as a guide to
detected objects or to mark areas with no objects. The diameter of the
circle can also be change in size by changing the D value.

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Full-screen Saved screenshot
The measured projects and created images can of course also be
uploaded to a computer (see the section on Transferring Data).
4.2 Migration settings and Images for 3D Projects
When the 3D project is ready, there are a number of different options
available on the screen, in addition to the filter settings explained above.
By pressing , the user can view
the settings of the project.

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By pressing the button, it
is possible to change the
Velocity settings (Migration) or
to create Image Slices.
Note! Make sure that a well-
defined hyperbola is visible in
the right hand screen before
entering the Velocity Settings
(Migration window).
Migration is a processing scheme which can significantly sharpen the
radar image, especially when seen in the top view. Using this option, an
appropriate velocity for the migration can be selected, by changing .
The is also a background removal filter for 3D project.
With the Image Slice Generator
images can be generated in freely
set depth ranges. See example
below.
The distance is given as the dist-
ance between the individual slices
created within the depth range.
The pictures are saved in an own catalogue, named as:
ProjectName_S0001, where 0001 will be a unique sequence number.
Example of how images can be saved.