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Automatic acquisition of aerial threats at thousands of kilometers distance requires high sensitivity
to small differences in contrast and high optical quality for subpixel resolution, since targets
occupy much less surface area than a single pixel. Targets travel at high speed and break up in
the re-entry phase. Target/decoy discrimination at the earliest possible time is imperative. Real
time performance requires a multifaceted approach with hyperspectral imaging and analog processing
allowing feature extraction in real time.
Hyperacuity Systems has developed a prototype chip capable of nonlinear increase in resolution
or subpixel resolution far beyond either pixel size or spacing. Performance increase is due to a
biomimetic implementation of animal retinas. Photosensitivity is not homogeneous across the
sensor surface, allowing pixel parsing. It is remarkably simple to provide this profile to detectors
and we showed at least three ways to do so. Individual photoreceptors have a Gaussian sensitivity
profile and this nonlinear profile can be exploited to extract high-resolution. Adaptive,
analog circuitry provides contrast enhancement, dynamic range setting with offset and gain control.
Pixels are processed in parallel within modular elements called cartridges like photo-receptor
inputs in fly eyes. These modular elements are connected by a novel function for a cell
matrix known as L4. The system is exquisitely sensitive to small target motion and operates
with a robust signal under degraded viewing conditions, allowing detection of targets smaller
than a single pixel or at greater distance. Therefore, not only is instantaneous feature extraction
possible but also subpixel resolution. Analog circuitry increases processing speed with more accurate
motion specification for target tracking and identification.
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