We present work on the development of a long range standoff concealed weapons detection system capable of imaging
under very heavy clothing at distances exceeding 100 m with a cm resolution. The system is based off a combination of
phased array technologies used in radio astronomy and SAR radar by using a coherent, multi-frequency reconstruction
algorithm which can run at up to 1000 Hz frame rates and high SNR with a multi-tone transceiver. We show the flexible
design space of our system as well as algorithm development, predicted system performance and impairments, and
simulated reconstructed images. The system can be used for a variety of purposes including portal applications, crowd
scanning and tactical situations. Additional uses include seeing through dust and fog.
The results of testing two technologies based on gas microplasmas for the generation of UV-visible light is
detailed. A microcavity device from the University of Illinois at Champaign-Urbana have been delivered with an Ar/D2
gas mixture. Emission from the Ar/Ne as well as an Ar/D2 eximer in the 250-400nm range, as well as argon lines in the
visible and near infrared, are measured. Development of addressing arrays is discussed as is the potential of emission in
other wavebands with other gas species. A 100x40 array of plasmaspheres combined with electronics capable of
projecting images at 1000 Hz with 10 bits of grayscale resolution has been built and tested. This system, built by
Imaging Systems Technology (IST), is capable of accepting DVI output from a HWIL system and projecting UV from a
gas captured in the spheres. This array uses an argon neon gas mixture to produce UV, visible and near infrared light.
Performance data discussed for both arrays include: maximum and minimum brightness, uniformity, spectral content,
speed, linearity, crosstalk, resolution, and frame rate. Extensions of these technologies to larger arrays with wider
spectral bandwidth for use in multispectral projectors are discussed.
Microplasma arrays for solar blind ultraviolet scene generation are being investigated in a Phase II SBIR program. An overview of the project and current status is presented. Preliminary work indicates that high flux with either spectral line or broadband radiant emission is possible. Two separate design approaches are being evaluated with array formats up to 100x100 planned for testing. Spectral emission from plasmas formed by multiple gas species have been characterized and several chosen for use in arrays. Design trades between parameters such as: frame rate, # bits of resolution, input power, flux levels, and gas species will be evaluated. The performance of a future system will be estimated.
There is an incredible amount of system engineering involved in turning the typical infrared system needs of
probability of detection, probability of identification, and probability of false alarm into focal plane array (FPA)
requirements of noise equivalent irradiance (NEI), modulation transfer function (MTF), fixed pattern noise (FPN), and
defective pixels. Unfortunately, there are no analytic solutions to this problem so many approximations and plenty of
"seat of the pants" engineering is employed. This leads to conservative specifications, which needlessly drive up system
costs by increasing system engineering costs, reducing FPA yields, increasing test costs, increasing rework and the
never ending renegotiation of requirements in an effort to rein in costs. These issues do not include the added
complexity to the FPA factory manager of trying to meet varied, and changing, requirements for similar products
because different customers have made different approximations and flown down different specifications.
Scene generation technology may well be mature and cost effective enough to generate considerable overall
savings for FPA based systems. We will compare the costs and capabilities of various existing scene generation systems
and estimate the potential savings if implemented at several locations in the IR system fabrication cycle. The costs of
implementing this new testing methodology will be compared to the probable savings in systems engineering, test,
rework, yield improvement and others. The diverse requirements and techniques required for testing missile warning
systems, missile seekers, and FLIRs will be defined. Last, we will discuss both the hardware and software requirements
necessary to meet the new test paradigm and discuss additional cost improvements related to the incorporation of these