The process creates the so-called
synthetic aperture that is much larger
than the length of the antenna.
‘Using knowledge of the signal that
you have transmitted, reflections from
the ground and how they are
propagated, it is possible to build up
terrain maps to image buildings
and different objects on the ground,’
said Phillips.
He was given responsibility for
ensuring that all the pieces of a new
SAR system worked in harmony.
‘One of my tasks was to act as a
systems integrator, ensuring that the
antenna system, the computer and the
acquisition systems of the SAR would
work together, as well as ensuring
that the various mechanical systems
positioned the antenna correctly,’
he said.
In most SAR applications, the
characteristics of the system are
sufficient to form high-resolution twodimensional
images. Obtaining three
dimensional images, however, is a
trickier challenge.
So as well as setting up the
equipment, another part of his task was
to examine the optimum way to acquire
and process data to generate threedimensional
synthetic imagery.
Not all radar equipment is used
aboard aircraft to take images of the
earth’s surface.
‘Such radar systems can also be
used to image objects in the ground,’
said Phillips. Indeed, SAR-based
systems, used in conjunction with other
imaging systems such as Ground-
Penetrating Radar (GPR), have proved
to be a highly effective technique in the
detection of unexploded ordnance.
Phillips has been involved in
developing algorithms for processing
the data received from the ground-
penetrating sensor systems to allow a
user to gain a clearer picture of what lies
beneath the surface.
He admitted that the experience he
had gained while at Southampton
University, where he helped develop a
novel algorithm for image registration,
had made the job easier.
Working life at DSTL is challenging
and diverse, said Phillips. ‘Because I’m
heavily involved in work involving Radio
Frequency (RF) signal transmission,
acquisition and processing, my skills are
applicable across a range of many
different projects. So I tend to focus on
a number of different projects
concurrently,’ he said.
In one such RF-related project,
Phillips was given the job of developing
a rugged handheld computer system
for the acquisition and processing of
RF signals.
‘The ability to work on
projects that you see
come to fruition quickly
is very satisfying’
‘The basic idea was to see if we
could use an off-the-shelf PDA or
tablet PC, add a custom-built
acquisition card and turn it into
multifunctional data capture and
analysis device,’ Phillips said.
Such a device would have obvious
benefits for the military, which now
needs to carry an array of equipment
such as spectrum analysers and
oscilloscopes to analyse systems in
the field.
A portable unit that served many
purposes would not only replace such
TECHNOLOGY HORIZONS SUMMER 2008 5
DEFENCE RESEARCH|TECHNOLOGY HORIZONS
devices but be easily transportable and
less expensive.
Phillips’ job was to analyse the
specifications of the equipment that
was in use and determine whether it
might be possible to reproduce the
same functionality in a portable device
by using commercial off-the-shelf
equipment.
Although the engineers in the
electronics department are involved in
the design and evaluation of RF
technologies and equipment, prior to
building and testing equipment they
often use EM modelling to investigate
the physical mechanisms at work in a
conceptual design.
So when he is not actually
developing electronic systems, Phillips
is exploring the design specifications
for new radar systems that can be used
by EM modelling experts to validate
and optimise.
‘EM modelling is often used for radar
simulations — if you can model a plane
and model the radar, for example, then
you can start to simulate the sort of
signals that you can expect back. That
removes some of the need to do
physical trials,’ said Phillips.
Phillips’ role is a demanding one.
‘But that’s exciting in some ways,
because I have to go out and learn new
ways of doing things, which is difficult
yet stimulating. If it wasn’t, it wouldn’t
be enjoyable,’ Philips said.
The work is also rewarding. ‘The
ability to work on projects that you can
see come to fruition quickly and that
have obvious benefits to our customers
is very satisfying,’ he said.
‘And because a lot of the work that
we do is in quite small teams, even a
Year In Industry student or a recent
graduate will be involved in interesting
research. That is really quite inspiring.’
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