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EO Systems
NOVEL DETECTORS
SUMMARY
This sub-theme addresses the development
of detector technologies to provide enhanced capabilities;
such as sensitivity, broader waveband coverage, and
other novel detectors such as low pixel count focal
plane arrays to investigate temporal signatures of targets.
MILITARY BENEFITS
The real military benefits for the
use of novel detectors are numerous. The main thrust is
to find more affordable solutions to the existing problems.
Additionally, sensor performance in many cases is limited
by resolution. If data can be extracted from sub-pixel
targets using spectral or temporal information, then resolution
restrictions will not be such an issue.
RESEARCH OBJECTIVE
Investigation of CMOS technology for low cost,
low power consumption, high dynamic range sensors
Extraction of temporal information of targets
using smart pixel arrays
Development of avalanche photodiodes capable
of rapid, high sensitivity imaging and range-finding
RESEARCH OUTLINE
The
aim of the research within this sub-theme is to investigate
a family of detector devices. This will improve the
ability of future sensing systems to operate at longer
ranges and improve identification probability at lower
cost than existing sensor systems.
CMOS detectors could be used in sights
where man portability is important. This requires low
power consumption and low weight. High dynamic range
will also allow the sensors to be used in a wider range
of lighting conditions than that achieved by current
image-intensified sights.
Conventional imaging sensors use spatial
information in order to recognise and identify a target.
Sensor technologies will be investigated that are able
to capture the temporal signature of a target using
low pixel count focal plane arrays. By comparing the
acquired signature with those in a database the target
can be recognised and identified. Heterodyne techniques
already established in the radio frequency domain will
be used to extract the temporal data of signatures of
interest. The detected optical signal is heterodyned
with a local oscillator and filtered in order to reduce
the bandwidth of the signal processed on the focal plane
array. This will allow the circuitry to be implemented
at pixel level.
Laser range receiver performance is
currently limited by the post-amplifier noise. Heterodyne
techniques can be used to improve the sensitivity but
the receiver then becomes more complex and more costly.
Devices will be studied that use avalanche techniques
that are capable of single photon detection at eye-safe
laser wavelengths. Such devices have the potential for
uncooled operation, low power consumption and high bandwidth.
Overall the longer term plan will
be to identify the current limitations of existing sensors
and identify technology gaps as they emerge. Further
proposals will address solutions to improve sensitivity,
multi-functionality, affordability, efficiency and reliability.
CO-ORDINATION WITH EXISTING /
PREVIOUS RESEARCH
QinetiQ are nearing completion of
a three year CRP contract investigating some of the
fundamentals of improving CMOS technology. The CMOS
aspect to this sub-theme will build on the results from
this work. QinetiQ have previously conducted work under
the CRP into temporal frequency pattern recognition
techniques. This has indicated that intensity information
up to the fifth harmonic component is required for identification
purposes. Finally, the APD development work will build
on preliminary work conducted under a MOD-sponsored
EPSRC project and a DERA Malvern supported seed-corn
project.
The
aim of the research within this sub-theme is to investigate
a family of detector devices. This will improve the
ability of future sensing systems to operate at longer
ranges and improve identification probability at lower
cost than existing sensor systems. 