AMR-June-July-2013

NIGHT VISION
T H E R M A L
I M A G E R Y
President of DRS Network and Imaging
Systems. “This award is a testament to the
hard work and dedication of DRS team
members to understanding our customer’s
requirements and developing, qualifying,
testing and producing a superior product.”
AWARE pushes
sensor performance
While sensor fusion and systems integration,
aided by Size, Weight and Power
(SWaP) improvements are paying dividends
and taking much of the limelight,
there is still much to come from basic sensor
performance. For example, thermal infrared
cameras continue to advance in directions
that will benefit the dismounted warfighter.
DRS Technologies' engineers working
under the auspices of DARPA’s Advanced
Wide-field-of-view Architectures for image
Reconstruction and Exploitation (AWARE)
programme have demonstrated an LWIR
camera whose detector elements are only
five microns across, DARPA announced in
mid-April. This, says the agency, means that
the pixels are about half the size of the photons
they detect, around one twelfth the
diameter of a human hair or one sixth of the
area of current state-of-the-art detector elements.
The detector chip is configured as a
1,280 x 720 focal plane array.
As with the visual cameras in the latest
smartphones, smaller pixels allow the
optical elements and packaging to be
made much smaller without sacrificing
sensitivity, resolution or field of view,
DARPA points out. A higher density of
pixels over a given area makes it easier to
capture the photons from, and thus
image, a target. The cumulative result is a
smaller, lighter and more portable LWIR
camera, the organisation elaborates.
Because the cost of focal plane arrays is
proportional to the chip area, making
Night vision devices are critical for
dismounted troops and the trend
towards multi-purpose, multi-spectral
systems promises more capability and
reduced physical burden © ITT Exelis
them smaller could also make them
cheaper. DARPA explains that because
the arrays are created on wafers of a given
size and cost, the smaller they are, the
more each wafer can yield and the lower
the unit cost of each array. This technology
could be a game changer as current
high-resolution LWIR cameras are too big
for a soldier to carry into battle and too
expensive for individual deployment.
The AWARE programme under which
the five-micron LWIR imager has been
demonstrated has been created to address
what DARPA describes as the immense
need to increase field of view, resolution
and day/night capability at reduced
SWaP and cost. The main driver, says the
organisation, is to provide dismounted
soldiers, ground troops and near-ground
support platforms with the best available
imaging tools to improve their combat
effectiveness. The AWARE programme’s
purpose is to push the envelope of imager
performance though new detector and
camera designs and ground support systems
that use advanced distributed aperture
sensors.
AWARE is also advancing sensors in
other parts of the infrared spectrum. The
High Operating Temperature MWIR
(HOT MWIR) effort, for example, seeks to
fill the performance, SWaP and cost gap
between uncooled and cooled sensors for
soldiers through the use of an MWIR
detector that, although cooled, operates at
a significantly higher temperature than the
80°K typical today. Made from Mercury
Cadmium Telluride (HgCdTe), it features
micro-miniature pixels and a small, battery-powered
cooler, a combination that
allows for a large format sensor in a small,
low power package. The detector material’s
sensitivity across the IR spectrum is
enabled, says DARPA, by new optics
developed to combine MWIR and SWIR
capabilities into a single platform. The first
application is a long-range handheld sight
with laser detecting capability.
“Never before has a MCT MWIR with
“see spot” capability been developed into
such small handheld sights and potentially
unequalled performance in future sniper
scopes,” explained Nibir Dhar, AWARE
programme manager. “The HOT-MWIR
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