3d-Radar Geoscope Mk4 User manual

3d-radar as
GeoScope™ User’s Manual
Model Geoscope Mk4
Document Version 2.0

3d-radar as

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page I Revision 2.0 Date: 02/07/2013
Contact Details
3d-Radar S
Klæbuveien 196B
NO-7037 Trondheim, Norway
([phone] Phone
([phone] Fax
www.3d-radar.com
Copyright and Trademarks
© 2002-2013, 3d-Radar S. ll rights reserved.
3d-Radar, GeoScope
TM
is a trademark of 3d-
Radar S. Microsoft, Windows, and Windows XP
are either registered trademarks or trademarks
of Microsoft Corporation in the United States
and/or other countries. ll other trademarks are
the property of their respective owners.
Release Notice
This is the March 2013 release of the GeoScope
User’s Manual. It applies to the GeoScope Mk4
radar. The following limited warranties give you
specific legal rights.
ardware Limited Warranty
3d-Radar warrants that this 3d-Radar hardware
product (the“Product”) shall be free from defects
in materials and workmanship and will
substantially conform to 3d-Radar’s applicable
published specifications for the Product for a
period of one (1) year, starting from the date of
delivery. The warranty set forth in this
paragraph shall not apply to software/firmware
products.
User Software and Firmware License,
Limited Warranty
This 3d-Radar User Software and/or Firmware
product (the “Software”) is licensed and not
sold. Its use is governed by the provisions of the
applicable End User License greement
(“EUL ”), if any, included with the Software. In
the absence of a separate EUL included with
the Software providing different limited warranty
terms, exclusions, and limitations, the following
terms and conditions shall apply. 3d-Radar
warrants that this 3d-Radar Software product
will substantially conform to 3d-Radar’s
applicable published specifications for the
Software for a period of ninety (90) days,
starting from the date of delivery.
Warranty Remedies
3d-Radar's sole liability and your exclusive
remedy under the warranties set forth above
shall be, at 3d-Radar’s option, to repair or
replace any Product or Software that fails to
conform to such warranty (“Nonconforming
Product”), or refund the purchase price paid by
you for any such Nonconforming Product, upon
your return of any Nonconforming Product to 3d-
Radar in accordance with 3d-Radar’s standard
return material authorization procedures.
Warranty Exclusions and Disclaimer
These warranties shall be applied only in the
event and to the extent that: (i) the Products
and Software are properly and correctly
installed, configured, interfaced, maintained,
stored, and operated in accordance with 3d-
Radar’s relevant operator's manual and
specifications, and; (ii) the Products and
Software are not modified or misused. The
preceding warranties shall not apply to, and 3d-
Radar shall not be responsible for defects or
performance problems resulting from (i) the
combination or utilization of the Product or
Software with products, information, data,
systems or devices not made, supplied or
specified by 3d-Radar; (ii) the operation of the
Product or Software under any specification
other than, or in addition to, 3d-Radar's
standard specifications for its products; (iii) the
unauthorized modification or use of the Product
or Software; (iv) damage caused by accident,
lightning or other electrical discharge, fresh or
salt water immersion or spray; or (v) normal
wear and tear on consumable parts (e.g.,
batteries).
THE W RR NTIES BOVE ST TE 3D-R D R'S
ENTIRE LI BILITY, ND YOUR EXCLUSIVE
REMEDIES, REL TING TO PERFORM NCE OF
THE PRODUCTS ND SOFTW RE. EXCEPT S
OTHERWISE EXPRESSLY PROVIDED HEREIN,
THE PRODUCTS, SOFTW RE, ND
CCOMP NYING DOCUMENT TION ND
M TERI LS RE PROVIDED “ SIS” ND
WITHOUT EXPRESS OR IMPLIED W RR NTY OF
NY KIND BY EITHER 3D-R D R S OR NYONE
WHO H S BEEN INVOLVED IN ITS CRE TION,
PRODUCTION, INST LL TION, OR
DISTRIBUTION, INCLUDING, BUT NOT LIMITED
TO, THE IMPLIED W RR NTIES OF
MERCH NT BILITY ND FITNESS FOR
P RTICUL R PURPOSE, TITLE, ND
NONINFRINGEMENT.
THE ST TED EXPRESS W RR NTIES RE IN
LIEU OF LL OBLIG TIONS OR LI BILITIES ON
THE P RT OF 3D-R D R RISING OUT OF, OR
IN CONNECTION WITH, NY PRODUCTS OR
SOFTW RE. SOME ST TES ND JURISDICTIONS
DO NOT LLOW LIMIT TIONS ON DUR TION OR
THE EXCLUSION OF N IMPLIED W RR NTY, SO
THE BOVE LIMIT TION M Y NOT PPLY TO
YOU.
Limitation of Liability
3D-R D R’S ENTIRE LI BILITY UNDER NY
PROVISION HEREIN SH LL BE LIMITED TO THE
GRE TER OF THE MOUNT P ID BY YOU FOR
THE PRODUCT OR SOFTW RE LICENSE. TO THE
M XIMUM EXTENT PERMITTED BY PPLIC BLE
L W, IN NO EVENT SH LL 3D-R D R OR ITS
SUPPLIERS BE LI BLE FOR NY INDIRECT,
SPECI L, INCIDENT L, OR CONSEQUENTI L
D M GES WH TSOEVER UNDER NY
CIRCUMST NCE OR LEG L THEORY REL TING
IN NY W Y TO THE PRODUCTS, SOFTW RE,
ND CCOMP NYING DOCUMENT TION ND
M TERI LS, (INCLUDING, WITHOUT
LIMIT TION, D M GES FOR LOSS OF BUSINESS
PROFITS, BUSINESS INTERRUPTION, LOSS OF
BUSINESS INFORM TION, OR NY OTHER
PECUNI RY LOSS), REG RDLESS OF WHETHER
3D-R D R H S BEEN DVISED OF THE
POSSIBILITY OF NY SUCH LOSS ND
REG RDLESS OF THE COURSE OF DE LING
WHICH DEVELOPS OR H S DEVELOPED
BETWEEN YOU ND 3D-R D R. BEC USE SOME
ST TES ND JURISDICTIONS DO NOT LLOW
THE EXCLUSION OR LIMIT TION OF LI BILITY
FOR CONSEQUENTI L OR INCIDENT L

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page II Revision 2.0 Date: 02/07/2013
D M GES, THE BOVE LIMIT TION M Y NOT
PPLY TO YOU.
Regulations and Safety
The GeoScope Ground Penetrating Radar
comprises a radar transmitter and receiver.
Regulations regarding the use of the radars vary
greatly from country to country. In some
countries, the unit can be used without obtaining
an end-user license. Other countries require
end-user licensing. Consult your local
communications governing agency for licensing
information. Before operating this radar,
determine if authorization or a license to operate
the unit is required in your country. It is the
responsibility of the end user to obtain an
operator’s permit or license for this Ground
Penetrating Radar for the location or country of
use.
STATEMENT ACCORDING FCC
This device complies with Part 15 of the FCC
Rules. Operation is subject to the following two
conditions: (1) This device may not cause
harmful interference, and (2) this device must
accept any interference received, including
interference that may cause undesired
operation.
Any changes or modifications not expressly
approved by 3d-Radar may void the user's
authority to operate the equipment.
STATEMENT ACCORDING INDUSTRY
CANADA
Per RSS-Gen, Section 7.1.3 This device complies
with Industry Canada license-exempt RSS
standard(s). Operation is subject to the following
two conditions: (1) this device may not cause
interference, and (2) this device must accept
any interference, including interference that may
cause undesired operation of the device.
This Ground Penetrating Radar Device shall be
operated only when in contact with or within 1 m
of the ground. This Ground Penetrating Radar
Device shall be operated only by law
enforcement agencies, scientific research
institutes, commercial mining companies,
construction companies, and emergency rescue
or firefighting organizations.
Selon RSS-Gen section 7.1.3, cet appareil est
conforme aux normes "Industry Canada license-
except RSS standards". Son fonctionnement est
soumis aux deux conditions suivantes: (1) cet
appareil ne doit pas provoquer d'interférences,
et (2) cet appareil doit accepter toute
interférence, y compris les interférences pouvant
provoquer un fonctionnement indésirable de
l'appareil.
Ce dispositif de radar à pénétration du sol ne
doit être utilisé que lorsqu'il est en contact avec
ou à moins de 1 m du sol. Il ne doit être mis
en œuvre que par les services officiels
d'investigation, les instituts de recherche
scientifique, les sociétés minières commerciales,
les entreprises de construction et les organismes
de secours d'urgence ou de lutte contre les
incendies.
Safety
EXPOSURE TO R DIO FREQUENCY R DI TION
The radiated power of the radar antenna is
approximately 10mW. This is a very low RF
power. However, we recommend to maintain a
minimum separation distance of 10 cm
(approximately 4 in.) between yourself and the
bottom side of the radiating GPR antenna to
avoid any harmful radiation levels.

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page 1 Revision 2.0 Date: 02/07/2013
Table of Contents
Table of Contents .................................................................................. 1
bbreviations ........................................................................................ 1
1 Introduction .................................................................................... 2
1.1 3d-Radar Technology .................................................................. 2
1.2 Collect up to 41 survey lines simultaneously .................................. 3
1.3 Multi-offset recording (optional) ................................................... 5
1.4 ccessories/options .................................................................... 6
2 Hardware Components ..................................................................... 8
2.1 GeoScope Unit ........................................................................... 8
2.2 ux connector ........................................................................... 9
2.3 GPS input .................................................................................. 9
2.4 Distance Measurement Instrument (DMI) .................................... 10
2.5 Power Supply........................................................................... 11
2.6 Control Computer ..................................................................... 11
3 ntenna rray ............................................................................... 13
3.1 ntenna Trailer ........................................................................ 13
4 Operation ..................................................................................... 16
5 Maintenance ................................................................................. 18
5.1 Cleaning air filter ..................................................................... 18
5.2 Cleaning of connectors .............................................................. 18
5.3 Cleaning the antenna array ....................................................... 18
Abbreviations
DMI Distance Measurement Instrument (encoder wheel)
GPR Ground Penetrating Radar
SFCW Step-frequency Continuous Waves
TX Transmitter
RX Receiver

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page 2 Revision 2.0 Date: 02/07/2013
1Introduction
This document contains the user manual for the GeoScope™ Mk4 ground
penetrating radar system, designed and manufactured by 3d-Radar S, see
http://www.3d-radar.com. The purpose of this document is to explain how to
assemble the hardware and use the GeoScope software. GPR and signal
processing theory is not covered by this manual. Some guidelines for
configuring the waveform will be provided.
1.1 3d-Radar Technology
The GeoScope is a three-dimensional step-frequency ground penetrating
radar. The GPR transmits electromagnetic waves through an antenna array
and measures the echo from layers and objects in the subsurface. The depth
of the objects is found by measuring the travel time from the signal is
transmitted until the echo is received. depth estimate is obtained by
multiplying this time with the wave velocity of the signal.
The GeoScope
TM
GPR is the fastest step-frequency radar on the market. By
using a digital frequency source instead of traditional phase-locked loop
technology, the GeoScope
TM
can generate waveforms from 140 MHz up to 3
GHz. The step-frequency technique has a coherent receiver which means that
the whole waveform length is used as 100% efficient integration time. By
comparison, impulse GPRs use stroboscopic sampling with significant loss of
energy. Figure 1 shows an overview of the GeoScope system with optional
GPS system.
Figure 1 - GeoScope GPR system overview.
The step-frequency waveform gives optimum source signature with a uniform
frequency spectrum. The computer control allows the user to set the dwell

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page 3 Revision 2.0 Date: 02/07/2013
time per frequency as well as the start and stop frequencies as shown in
Figure 2. The GeoScope sequentially transmits one complete waveform on
each transmitting antenna while receiving on the corresponding receiving
antenna. The transmission of one complete waveform on one transmitting
element is called as scan. The recorded frequency domain data contain one
complex value for each frequency in the waveform.
The radar system performs real-time time domain conversion through Fast
Fourier Transform allowing the user to view radargrams from the antenna
array. These data can be imported into either 3dR Examiner software, or
RoadDoctor
TM
from Roadscanners OY.
Figure 2 - Step-frequency waveform.
The radar is controlled from a laptop computer through an Ethernet cable.
The system can also be configured with GPS/Total Station interface (option)
to allow recording of position data through the serial port (RS-232).
1.2 Collect up to 41 survey lines simultaneously
The GeoScope
TM
GPR is designed to operate with an electronically scanned
antenna array with up to 41 antennas. The antennas are scanned
sequentially by the radar. The unique antenna system consists of air-coupled
bow-tie monopole pairs as shown in Figure 3. This gives a quasi-monostatic
antenna configuration with practically zero-offset distance. The air-coupled
antenna array can be operated at elevations up to 50cm off the ground
allowing high-speed surveys.
Figure 1 shows the spatial sampling grid for a typical 3D radar survey. The
Distance Measurement Instrument (DMI) outputs a trigger signal to the
system every time the array has moved the specified interval along the x-
axis. The horizontal sampling interval determines the ∆x in the sampling grid.
The array is aligned along the y-axis. The spacing between the antenna
elements in the array gives the ∆y in the sampling grid.
time
N frequencies
frequency
Frequency step
Dwell Time
Scan Time (for one single antenna element)
3.0 GHz
140 MHz

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page 4 Revision 2.0 Date: 02/07/2013
Figure 3 - Ultra-wideband bow-tie antenna pair (cross section).
s opposed to traditional octave-band GPR antennas, the ultra-wideband
bow-tie monopoles have continuous frequency coverage from the 200 MHz
range up to 3 GHz as illustrated in Figure 4. In practice this allows the user to
collect data from 140 MHz to 3 GHz without changing antennas. By
comparison, a similar survey using impulse GPR would require use of
200MHz, 400 MHz, 800 MHz and 1600 MHz antennas.
Figure 4 - Wideband coverage of the 3d-Radar antenna array.
The antenna elements are arranged in a linear array as shown in Figure 5
where the transmitting and receiving antennas are displaced to each other.
During the survey, the radar combines the transmit/receive antennas
sequentially to obtain a number of profiles (or channels) as shown in Figure
5.
TX Radiation pattern RX Radiation pattern
Common footprint
3d-Radar frequency response:
100MHz 200MHz 400MHz 800MHz
1200MHz

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page 5 Revision 2.0 Date: 02/07/2013
Figure 5 – Antenna layout DX2429.
The standard range of antenna arrays includes the following models:
Model DX0909
DX1213 DX1821 DX2125 DX2429 DX3341
Length (mm) 900 1200 1800 2100 2400 3300
Channels 9 13 21 25 29 41
Figure 6 – Available antenna models.
1.3 Multi-offset recording (optional)
The Multi-offset recording allows the user to set up antenna scanning
sequences with independent transmitter and receiver antenna locations.
In the standard (zero-offset) antenna scanning sequence, the GeoScope
transmits/receives sequentially on each antenna pair. Data is collected in the
1 152 3 4 5 6 7 8 9 10 11 12 13 14
Ch# 1 2 3 4 5 ... 25 26 27 28 29
Tx# 1 2 2 3 3 ... 13 14 14 15 15
Rx# 1 1 2 2 3 ... 13 13 14 14 15
1 152 3 4 5 6 7 8 9 10 11 12 13 14

3d-radar as
GeoScope
TM
User’s Manual
© 2013 3d-Radar S Page 6 Revision 2.0 Date: 02/07/2013
transverse direction by firing the antenna pairs in a linear sequence from
ntenna Pair #1 to the highest antenna pair.
With the Multi-offset feature, the system offers a higher degree of freedom to
build more advanced scan patterns. It is for example possible to transmit at
ntenna #1 and receive at ntenna # 8, (i.e. with an offset distance along
the cross-line direction). The automatic Common-Mid-Point (CMP) gather
collects traces centered at the antenna in the center of the array with
increasing offsets (normal move-out) as shown in Figure 7. This feature is
used to estimate the wave velocity using standard methods (semblance
analysis) used in seismic processing. Other scan sequences can be
programmed as well. Note that this mode of operation works in a sequential
manner, hence using all possible combinations of transmitter and receiver
antennas will slow down the data collection speed somewhat.
Figure 7 – Common-Mid-Point Gather.
1.4 Accessories/options
The GeoScope
TM
can be used in combination with digital video camera, GPS
and CamLink
TM
software from RoadScanners for simultaneous recording of
video, GPR data and GPS data.
The antenna array can be equipped with a 2-wheel lightweight trailer
assembly (Figure 8). The trailer connects to a standard ISO 50mm ball hitch
used on cars. For railway operation 3d-Radar can provide railway wheels with
adjustable track width. For high-speed surveys we recommend to mount the
array directly to the vehicle
Figure 8 - Typical GPR setup with a 2-wheel trailer.