| Nonlinear Optical Dynamic Range Compression with Thin-Film Organic Photorefractive Material |
30 Jan 2009 |
18 pages |
| Authors:
Bahareh Haji-saeed; John Kierstead; Jed Khoury; Charles Woods; Nasser Peyghambarian; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
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 | Nonlinear information processing via two-beam coupling using thin-film organic photorefractive material is demonstrated. The organic material is found to possess superior response time and resolution compared to photorefractive bulk material. The possibility of designing dynamic range compression deconvolution for restoring blurred images embedded in a noisy environment is also demonstrated |
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| Dynamic Range Compression Deconvolution for Enhancement of Automatic Target Recognition System Performance |
03 JUN 2008 |
11 pages |
| Authors:
Jed Khoury; Bahareh Haji-saeed; Charles L. Woods; John Kierstead; William Goodhue; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
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| A generic nonlinear dynamic range compression deconvolver (DRCD) is proposed. We have performed the dynamic range compression deconvolution using three forms of nonlinearities: (1) digital implementation- A-law/ -law, (2) hybrid digital-optical implementation- two-beam coupling photorefractive holography, and (3) all optical implementation- MEMS deformable mirrors. The performance of image restoration improves as the saturation nonlinearity increases. The DRCD could be used as a preprocessor for enhancing Automatic Target Recognition (ATR) system ... |
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| Power-Law Radon-Transformed Superimposed Inverse Filter Synthetic Discriminant Correlator for Facial Recognition |
MAR 2008 |
8 pages |
| Authors:
Bahareh Haji-saeed; Jed Khoury; Charles L. Woods; John Kierstead; SOLID STATE SCIENTIFIC CORP HOLLIS NH
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| A power-law correlation based on an inverse filter Fourier-Radon-transform synthetic discriminant function (SDF) for facial recognition is proposed. In order to avoid spectral overlap and nonlinear crosstalk, superposition of rotationally variant sets of inverse filter Fourier-transformed Radon-processed templates is used to generate the SDF. For the inverse filter, the Fourier transform of M projections (Radon Transform) from one training image is combined with (N-1) M Fourier transform of M projections ... |
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| Two-Beam Coupling Correlation Synthetic Aperture Radar Image Recognition with Power-law Scattering Centers Pre-Enhancement |
MAR 2008 |
11 pages |
| Authors:
Bahareh Haji-saeed; Jed Khoury; Charles L. Woods; John Kierstead; SOLID STATE SCIENTIFIC CORP HOLLIS NH
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| Synthetic radar image recognition is an area of interest for military applications including automatic target recognition, air traffic control, and remote sensing. Here a dynamic range compression two-beam coupling joint transform correlator for detecting synthetic aperture radar (SAR) targets is utilized. The joint input image consists of a pre-power-law, enhanced scattering center of the input image and a linearly synthesized power-law enhanced scattering center template. Enhancing the scattering center of ... |
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| A-law/Mu-law Dynamic Range Compression Deconvolution (Preprint) |
04-Feb-2008 |
39 pages |
| Authors:
Bahareh Haji-saeed; Jed Khoury; William D Goodhue; Charles L Woods; John Kierstead; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
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| In this paper the A-law/Mu-law Dynamic Range Compression algorithm used in telecommunication systems is proposed for the first time for nonlinear Dynamic Range Compression image restoration of blurred signals embedded in very high noise environment. Our simulation results demonstrate that the dynamic range compression image deconvolution via the A-law/Mu-law outperforms image restoration based on the well-established image restoration filters that have been used for the last fifty years such as ... |
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| MEMS based Optical Limiter (PREPRINT) |
28-Jan-2008 |
15 pages |
| Authors:
Bahareh Haji-saeed; Jed Khoury; John Kierstead; William D Goodhue; Charles L Woods; AIR FORCE RESEARCH LAB HANSCOM AFB MA OPTOELECTRONIC TECHNOLOGY BRANCH
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| In this paper we propose the design of a MEMS-deformable-mirror based optical limiter. The design is based on aperturing focused light reflected out of an optically driven deformable mirror, deformed in a parabolic form. We derived an expression for the reflected light intensity and we showed that the reflected light saturates as a function of back illumination light intensity. |
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| Binary Chirped Grating Diffractive Element for Sinusoidal to Linear Scanning Conversion: The Beam Propagation Design (Preprint) |
28-Jan-2008 |
15 pages |
| Authors:
Bahareh Haji-saeed; William Bailey; John Kierstead; Jed Khoury; Charles L Woods; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
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| We fabricated and tested our previously designed optical correction element with zoom capability to convert nonlinear sinusoidal scans into linear scans. The design methodology is based on derivating a graded index of refraction device as a reference design and converting the graded index of refraction into an amplitude or phase binarized diffractive element. Our graded index of refraction derivation is based on the propagation of an electromagnetic wave in an ... |
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| A Refractive-Diffractive Element Design for Resonant Scanner Angular Correction: The Symmetric Beam Retardation Approach (Preprint) |
18-Jan-2008 |
31 pages |
| Authors:
Bahareh Haji-saeed; Jed Khoury; Charles L Woods; John Kierstead; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
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| We propose a new approach for designing diffractive optical corrective elements with zooming capability to convert nonlinear sinusoidal scanning into linear scanning. Such devices will be useful for linearizing the angular scan of a resonant mirror scanner. The design methodology is to create a graded index of refraction device as the reference design, with its index of refraction parameters based on beam retardation through propagation in an inhomogeneous media. In ... |
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| Smart Optical Receiver for Beamforming and Enhancement of Field of View in LADAR Systems |
2008 |
8 pages |
| Authors:
Jed Khoury; Bahareh Haji-saeed; Charles L. Woods; John Kierstead; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE/ELECTROMAGNETICS TECHNOLOGY DIV
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| We propose using the smart antenna principle as the basis of a new design for smart optical receivers in LADAR systems. This paper demonstrates the feasibility of designing a LADAR system with a receiver consisting of an array of photodetectors, which leads to field-of-view enhancement and beamforming by fusing streams of video information received from the detectors. As a proof of concept, we demonstrate this design by fusing several video ... |
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