Measurement of oxygen saturation has proved to give important information about the eye health and the onset of eye pathologies such as Diabetic Retinopathy. Recently, we have presented a multi-aperture system enablin...
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A long wave infrared (LWIR) division of amplitude imaging Stokes polarimeter is presented. For the first time, to our knowledge, application of microbolometer focal plane array (FPA) technology to polarimetry is demon...
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Monostatic reflectance distribution function and Mueller matrix measurements were made of automobile panel samples using a polarimetric laser reflectometer and a spectropolarimeter, and roughness measurements were mad...
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ISBN:
(纸本)9780819471635
Monostatic reflectance distribution function and Mueller matrix measurements were made of automobile panel samples using a polarimetric laser reflectometer and a spectropolarimeter, and roughness measurements were made using a surface profilometer. The spectropolarimeter measurements were made over the range 0.7 to 2.6 mu m in the near and short wave infrared, and the laser measurements were made at 1.06 mu m. Depolarization indices for all polarimetric measurements were calculated.
A four camera Stokes imaging polarimeter operating in the visible at 60 frames per second will be presented. The polarimeter makes use of a beam splitter design which allows the measurement of a full Stokes vector ima...
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ISBN:
(纸本)9780819471635
A four camera Stokes imaging polarimeter operating in the visible at 60 frames per second will be presented. The polarimeter makes use of a beam splitter design which allows the measurement of a full Stokes vector image (S0, S1, S2, and S3). The system measures four images of a scene simultaneously. The polarimeter design, calibration procedures, and initial data from the instrument are presented.
This paper presents the design of a visible band imaging polarimeter that can also function as a low light level intensity imager. The polarimeter is based on the division of aperture approach, acquiring four subimage...
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ISBN:
(纸本)9780819468307
This paper presents the design of a visible band imaging polarimeter that can also function as a low light level intensity imager. The polarimeter is based on the division of aperture approach, acquiring four subimages simultaneously on a single CCD array. The system is currently designed to measure the first three normalized components of the Stokes vector through polarization filtering on three of the four available channels. The fourth channel remains unfiltered for radiometric sensing in low power situations. The opto-mechanical design allows for ease of assembly without requiring active alignment techniques, while maintaining a modular system. The modular nature provides a robust, flexible sensor that can be tailored to multiple applications.
Data from a recent "first-look" at using Long Wave InfraRed Imaging Polarimetry (LWIR-IP) to detect surface swimmers is presented and discussed. A significant increase in detection SNR over conventional IR i...
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Data from a recent "first-look" at using Long Wave InfraRed Imaging Polarimetry (LWIR-IP) to detect surface swimmers is presented and discussed. A significant increase in detection SNR over conventional IR imaging techniques was discovered. The physical phenomena that produces the increased SNR is discussed along with data that shows range effects and their degradation on the SNR. Most significantly, a method to classify the detected object using the same dataset is discussed. Augmenting current swimmer detection systems using this technique will likely significantly decrease the false alarm rates of the system, thus saving manpower resources and preserving force readiness.
Imaging polarimetry has the potential to be a key sensor technology in a number of target detection applications. Imaging polarimeters measure the polarization state of light emitted from and/or reflected from scenes....
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Imaging polarimetry has the potential to be a key sensor technology in a number of target detection applications. Imaging polarimeters measure the polarization state of light emitted from and/or reflected from scenes. The light is polarized because of the geometry, roughness and material properties of the objects embedded in the scene. This added information enhances conventional intensity and color imagery, potentially surpassing its performance in low contrast situations. In this paper, we describe a divided aperture MWIR imaging polarimeter which acquires multiple polarization images simultaneously. At the heart of the polarimeter is a relay lens set that produces four identical images on a single focal plane array from a single aperture. Each of the four images measures a different orientation of linear polarization, 0, 45, 90 and 135 degrees. The relay lens set operates inside of a pour fill Dewar of a InSb MWIR camera. The design and calibration method for the polarimeter are given along with example data sets taken from the air over Huntsville, AL.
A Pulse Coupled Neural Network (PCNN) has been developed in order to segment image data to reduce the amount of downstream processing. This paper discusses the results of applying the PCNN algorithm to data generated ...
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ISBN:
(纸本)0819455016
A Pulse Coupled Neural Network (PCNN) has been developed in order to segment image data to reduce the amount of downstream processing. This paper discusses the results of applying the PCNN algorithm to data generated by various sensor platforms. The PCNN algorithm was applied to data generated by a Long Wave Infrared Imaging Polarimeter. The PCNN correctly identified the concealed vehicles and the disturbed earth and rejected 96% of the remaining pixels because they had no information content. Next, the results of applying the PCNN algorithm to noisy infrared seeker data are presented. The PCNN correctly identified the target even though the background was quite noisy. Finally, the PCNN algorithm was applied to images containing solar glint. It correctly passed only 3% of the pixels to the downstream target/glint decision algorithm. To obtain maximum data throughput, the PCNN can be implemented in hardware.
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