The morphology of three-dimensional foams is of interest to physicists, engineers, and mathematicians. It is desired to image the 3-dimensional structure of the foam. Many different techniques have been used to image the foam, including magnetic resonance imaging, and short-focal length lenses. We use a camera and apply tomographic algorithms to accurately image a set of bubbles. We correct for the distortion of a curved plexiglas container using ray-tracing.
We replace the traditional grating used in a dispersive spectrometer with a multiplex holographic grating to increase the spectral range sensed by the instrument. The multiplexed grating allows us to measure three different, overlapping spectral bands on a color digital focal plane. The detector's broadband color filters, along with a computational inversion algorithm, let us disambiguate measurements made from the three bands. The overlapping spectral bands allow us to measure a greater spectral bandwidth than a traditional spectrometer with the same sized detector. Additionally, our spectrometer uses a static coded aperture mask in the place of a slit. The aperture mask allows increased light throughput, offsetting the photon loss at the broadband filters. We present our proof-of-concept dispersion multiplexing spectrometer design with experimental measurements to verify its operation.
We recently implemented a heterogeneous network of infrared motion detectors and an infrared camera for the detection, localization, tracking, and identification of human targets. The network integrates dense deployments of low cost motion sensors for target tracking with sparse deployments of image sensors for target registration. Such networks can be used in tactical applications for local and distributed perimeter and site security. Rapid deployments for crisis management may be of particular interest. This paper focuses particularly on the need for applications that deal with relatively dense and complex source fields such as crowds move through sensor spaces.
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