Radar

Whilst the different applications of Impulse Radar are numerous, at Impulse
Geophysics, the technique is predominantly applied to subsurface
investigations on transport networks and structures, such as [Roads],
[Railways], [Runways], [Bridges] and [Tunnels].

ROADS, RUNWAYS & TUNNELS

Impulse Radar is applied to roads, runways and tunnels in much the same way,
thus for conciseness, the following information applies to all three features.

When applied to roads, an Impulse Radar survey can accurately establish the
construction and condition information of a particular road up to 2 metres
beneath the surface. The survey is non-destructive and non-disruptive, as
data is collected at traffic speed and requires no traffic management.

More specifically, the following information can be gained from carrying out an
Impulse Radar Survey on a road:

Construction Information:
Layer & Material Changes
Layer & Material Types
Layer & Material Thickness/Depths
[Moisture Profiles]
De-lamination and De-bonding
Subsurface Consolidation
Voiding

SURVEY METHOD/DATA COLLECTION – Radar antennae are rack-mounted to
the rear of a survey vehicle and are placed just above the road surface
(25mm) in offside and nearside wheel track positions. The antennae are
connected by cable to the receiving equipment inside the vehicle. Once set
up, the survey vehicle is able to travel at traffic speed whilst the radar data is
being collected.
The survey equipment is relatively small and can be carried as normal flight
baggage thus making surveys abroad possible and affordable. Surveys can be
undertaken in all but the worst weather conditions and at anytime of the day
or night.

DATA PROCESSING – High quality data processing is essential for an
accurate assessment of a roads condition and construction. The key factors
to ensure that this is achieved are firstly experienced interpretation staff
and secondly efficient and effective software routines to run the raw data
through, ‘cleaning up’ and removing any unnecessary interferences to the
relevant data.

As pioneers of high-speed Impulse Radar on roads, Impulse Geophysics have
extremely experienced data processing and interpretation staff. Furthermore,
Impulse Geophysics has designed and developed unique and innovative
software routines to process and aid interpretation of the complex data. This
advanced processing yields better quality data and hence improves the
accuracy than that achieved by a standard radar survey using standard
issue software.

These two crucial factors are fundamental to an accurate assessment of a
road, and the ability of Impulse Geophysics to meet these criteria is the
justifiable reason that Impulse Geophysics prides itself as the UK’s leading
supplier of Impulse Radar surveys.

DATA PRESENTATION & REPORTING – The final presentation of data is
ultimately determined by the specifications of the end client. Impulse
Geophysics can present in all [industry standard formats], as well as being
highly adaptable and able to tailor final presentation to formats most
appropriate to the specific survey intentions. This includes incorporating
radar data with clients Pavement Management Systems (PMS).
As well as presenting radar data to the clients’ requirements, the data will
also be presented in WINRS (Windows Roadshow). WINRS is part of the
Impulse Geophysics reporting package and is unique to Impulse Geophysics
with the software being supplied at no extra charge.

WINRS was written to take advantage of the multi application environment
of Windows and in particular the Multiple Document Application (MDA)
capabilities of Windows. This software uses MDA in the main window to allow
up to 6 interpretation windows to be open simultaneously to enable
comparison of different lanes and/or carriageways or wheel tracks -
dependent on the survey data collected.

The interpretation window can view any part of the survey interpretation
and any chainage can be viewed with a slide-bar control, a single step (user
selectable step chainage) or selecting a node reference from a drop-down
combination box. Tick marks under the slide-bar also indicate the position of
node points along the survey length. A read out next to the node point
shows the offset chainage from that node point to the current cursor
position. Similar readouts at the top of the window show material type at the
cursor depth and the actual cursor depth.

From WINRS, the data can be exported to any of the [industry standard
formats] such as HAPMS, HMDIF. Additionally, WINRS facilitates colour coded
and annotated depth cross-sections to be printed from any Windows default
printer or in DXF (Autocad) format.

Ultimately radar data will be presented as the client demands, and such is
the flexibility of WINRS that Impulse Geophysics can guarantee that any
required output can be catered for and exported from WINRS.

RAILWAYS

In 2000 Impulse Geophysics, in conjunction with Railtrack and Scott Wilson,
carried out trials using high-speed Impulse Radar on railways to determine,
firstly whether Radar could be applied to the railways and secondly what
useful information could be obtained from the resultant data. The trials
conclusively proved that high-speed Impulse Radar could be applied to the
railways by using antennae arrays and configurations unique to Impulse
Geophysics and that the following information could be accurately obtained
from the resultant data:

Information which can accurately be obtained from a high-speed Impulse
Radar survey on the railways

* Ballast Thickness
* Areas of Increased Moisture
* Areas of Contaminated/Dirty Ballast

Following the trials Impulse Geophysics gained certification from Railtrack for
the unique equipment and antennae configuration on December 8th 2000.

[Railway Video Interface Here]

DATA COLLECTION – Similarly to road surveys, the unique antennae
configuration is mounted to a traveling train using a specifically designed
mounting device. Data can be collected up to speeds of 120 mph, therefore
the data can be collected on any scheduled train service as the train travels
its normal route without causing disruption to service.
DATA PROCESSING – Software routines have been developed to remove any
possible interference to data interpretation from railway tracks and sleepers
thus ensuring that final interpretation is as unhindered comprehensive and
accurate as possible.

DATA PRESENTATION & REPORTING – Data is presented in WINRS, the
Impulse Geophysics software package that enables interrogation of data and
facilitates various print off options.

Data can also be presented by way of small and large format illustrations,
drawings and plans as well as in Excel spreadsheets. Ultimately it is the
client who determines how data is to be best presented to fit into their
particular management/maintenance system and Impulse Geophysics will
tailor final presentation and reporting to these requirements. Finally a writing
report will accompany all drawings and CD ROMs.

BRIDGES & STRUCTURES

Impulse Geophysics have developed a 3 Ghz antenna, believed to be the only
one of its kind in the world. This unique antenna is designed to locate thin
surfacing layers (as thin as 25mm) and shallow reinforcements. Its readings
are accurate to a depth of approximately 300mm and it is therefore
superlative for non-destructive investigations of bridges and structures.

[Severn Bridge Jpg] Impulse Geophysics were commissioned to inspect the
new Severn Bridge before it was opened to the public.

The following bridge and structure information can be gained from a 3 Ghz
radar investigation:

* Layer Thickness (as thin as 25mm)
* Construction Detail
* Reinforcement Detail
* Areas of Moisture
* Voiding

Whilst it is accepted within the radar industry that radar is a suitable,
accurate method for non-destructive investigations of bridges and structures
and that it can establish the information above, wider recognition has also
come from Government, Construction Industry and Civil Engineering groups.
This wider recognition is welcomed and is fundamental to the pursuit of
applying radar to non-destructive bridge and structure investigations.

DATA COLLECTION – Data collection simply entails sweeping the antenna
over the targeted area as the data is fed back to a portable control unit.
This data can be viewed at the time for an on site appraisal, or returned to
the laboratory for more detailed processing.

DATA PROCESSING – The resultant data is run through unique software
processing routines to ‘clean up’ the data by removing any unnecessary
interference. This is done in order to facilitate unhindered and thorough
interpretation of the data.

DATA PRESENTATION & REPORTING – Data presentation can be tailored to
be compatible with client outputs and will also be presented on graphically
annotated plans and cross-sections.