David J. Brady

Conference Proceedings of SPIE the International Society for Optical Engineering · March 5, 2026 The focal field in incoherent imaging systems is undersampled by conventional focal planes. The field contains multidimensional coherence, spectral, polarization, and focal information that cannot be captured by uniform irradiance sampling. Metaoptics inte ... Full text Cite

Low latency streaming from a multi-camera array to a UHD display wall

Conference Proceedings of SPIE the International Society for Optical Engineering · March 5, 2026 This work presents a high-throughput pipeline for the low-latency streaming and visualization of ultra-high-definition (UHD) media captured by array camera systems. By utilizing diverse configurations such as multifocal, multi-spectral, and mixed color/mon ... Full text Cite

Real-time detection and tracking by an array camera with distributed neural processing

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2025 An intelligent array camera capable of detecting, identifying and tracking anomalies requires real-time processing in a distributed architecture. It also requires a robust, abstract feature space that a central”brain” can probe for prior features. An algor ... Full text Cite

Ptychographic Wavefront Sensing with a Camera Array and Diffraction Grating

Conference Propagation Through and Characterization of Atmospheric and Oceanic Phenomena Proceedings Optica Imaging Congress 2025 · January 1, 2025 A nine-aperture camera array which captures field information through a common diffraction grating is deployed to achieve ptychographic wavefront estimation and dynamic refocusing of a converging beam through a circular planar object. ... Full text Cite

Near-Real Time Stitching for a Multifocal Camera Array

Conference Computational Optical Sensing and Imaging Cosi 2025 in Proceedings Optica Imaging Congress 2025 3D Dh Cosi is Pcaop Radit Part of Optica Imaging Congress · January 1, 2025 We demonstrate a proof-of-concept for near-real-time stitched video from a multi-focal heterogeneous camera array. Hardware acceleration enables high-resolution panoramic frames at ∼5 frames per second, demonstrating feasibility for streaming. ... Full text Cite

RiFT - Radiance Field Tomography

Conference Is and T International Symposium on Electronic Imaging Science and Technology · January 1, 2024 Regression-based radiance field reconstruction strategies, such as neural radiance fields (NeRFs) and, physics-based, 3D Gaussian splatting (3DGS), have gained popularity in novel view synthesis and scene representation. These methods parameterize a high-d ... Full text Cite

Radiance Field Sampling for Unresolved Specular Object Classification

Conference 2024 IEEE Research and Applications of Photonics in Defense Conference Rapid 2024 Proceedings · January 1, 2024 We introduce a novel technique for classifying unresolved specular objects. In remote sensing targets of interest like drones, helicopters, planes, cars, or satellites are often under-resolved. If those targets have specular surface characteristics, like m ... Full text Cite

Specular Reflections for Classification of Unresolved Surfaces

Conference Laser Applications to Chemical Security and Environmental Analysis Lacsea 2024 in Proceedings Optica Sensing Congress 2024 Ais Lacsea Sensors Qsm Part of Optica Sensing Congress · January 1, 2024 Unresolved specular surfaces can be classified b y s ampling t heir radiance field. We present a way of distinguishing between two unresolved reflective targets. This is applicable for target identification in unresolved remote sensing situations. ... Cite

Metalens-based snapshot ptychography

Conference Laser Applications to Chemical Security and Environmental Analysis Lacsea 2024 in Proceedings Optica Sensing Congress 2024 Ais Lacsea Sensors Qsm Part of Optica Sensing Congress · January 1, 2024 We demonstrate a wavefront camera using a metalens. The metalens consists of a 5 by 5 array of overlapping focal apertures. We use a hybrid neural phase retrieval algorithm to image remote complex valued fields. ... Cite

Metalens-based snapshot ptychography

Conference 3D Image Acquisition and Display Technology Perception and Applications 3D 2024 in Proceedings Optica Imaging Congress 2024 3D Aoms Cosi ISA Pcaop Part of Optica Imaging Congress · January 1, 2024 We demonstrate a wavefront camera using a metalens. The metalens consists of a 5 by 5 array of overlapping focal apertures. We use a hybrid neural phase retrieval algorithm to image remote complex valued fields. ... Cite

Specular Reflections for Classification of Unresolved Surfaces

Conference 3D Image Acquisition and Display Technology Perception and Applications 3D 2024 in Proceedings Optica Imaging Congress 2024 3D Aoms Cosi ISA Pcaop Part of Optica Imaging Congress · January 1, 2024 Unresolved specular surfaces can be classified b y s ampling t heir radiance field. We present a way of distinguishing between two unresolved reflective targets. This is applicable for target identification in unresolved remote sensing situations. ... Cite

Specular Reflections for Classification of Unresolved Surfaces

Conference Quantum Sensing and Metrology, QSM 2024 in Proceedings Optica Sensing Congress 2024, AIS, LACSEA, Sensors, QSM - Part of Optica Sensing Congress · January 1, 2024 Unresolved specular surfaces can be classified b y s ampling t heir radiance field. We present a way of distinguishing between two unresolved reflective targets. This is applicable for target identification in unresolved remote sensing situations. ... Cite

Metalens-based snapshot ptychography

Conference Quantum Sensing and Metrology, QSM 2024 in Proceedings Optica Sensing Congress 2024, AIS, LACSEA, Sensors, QSM - Part of Optica Sensing Congress · January 1, 2024 We demonstrate a wavefront camera using a metalens. The metalens consists of a 5 by 5 array of overlapping focal apertures. We use a hybrid neural phase retrieval algorithm to image remote complex valued fields. ... Cite

Specular Reflections for Classification of Unresolved Surfaces

Conference Quantum Sensing and Metrology Qsm 2024 in Proceedings Optica Sensing Congress 2024 Ais Lacsea Sensors Qsm Part of Optica Sensing Congress · January 1, 2024 Unresolved specular surfaces can be classified b y s ampling t heir radiance field. We present a way of distinguishing between two unresolved reflective targets. This is applicable for target identification in unresolved remote sensing situations. ... Full text Cite

Metalens-based snapshot ptychography

Conference Quantum Sensing and Metrology Qsm 2024 in Proceedings Optica Sensing Congress 2024 Ais Lacsea Sensors Qsm Part of Optica Sensing Congress · January 1, 2024 We demonstrate a wavefront camera using a metalens. The metalens consists of a 5 by 5 array of overlapping focal apertures. We use a hybrid neural phase retrieval algorithm to image remote complex valued fields. ... Full text Cite

Differentiable Holography and its Development

Conference Frontiers in Optics Fio 2024 in Proceedings Frontiers in Optics Laser Science 2024 Fio Ls Part of Frontiers in Optics Laser Science 2024 · January 1, 2024 We show that differentiable holography allows for inline single-shot complex field imaging, high-performance pixel super-resolution lensless imaging, and denser volumetric particle velocimetry in a single shot. ... Cite

Silicon Photonics-Based All-Optical Image Compression

Conference 2023 Conference on Lasers and Electro Optics CLEO 2023 · January 1, 2023 We demonstrate an all-optical image compression technique using on-chip nanophotonic disordered media to perform local random transformations. Our compression technique is fast, scalable, and may consume about 50 times less energy than electronic compressi ... Cite

Boosting Graph Contrastive Learning via Graph Contrastive Saliency

Conference Proceedings of Machine Learning Research · January 1, 2023 Graph augmentation plays a crucial role in achieving good generalization for contrastive graph self-supervised learning. However, mainstream Graph Contrastive Learning (GCL) often favors random graph augmentations, by relying on random node dropout or edge ... Cite

Silicon Photonics-Based All-Optical Image Compression

Conference CLEO Science and Innovations CLEO S and I 2023 · January 1, 2023 We demonstrate an all-optical image compression technique using on-chip nanophotonic disordered media to perform local random transformations. Our compression technique is fast, scalable, and may consume about 50 times less energy than electronic compressi ... Full text Cite

High-speed compressive video via temporal-coding illumination

Conference Computational Optical Sensing and Imaging in Proceedings Optica Imaging Congress 3D Cosi Dh Flatoptics is Pcaop Part of Imaging and Applied Optics Congress 2023 · January 1, 2023 We describe video snapshot compressive imaging using infrared LED illumination. In baseball pitch tracking experiments, we demonstrate 16x improvement in temporal sampling rate. Infrared modulation enables coded illumination without affecting visible image ... Full text Cite

An scalable coding strategy for high resolution snapshot compressive temporal imaging at high compression ratios

Conference Computational Optical Sensing and Imaging in Proceedings Optica Imaging Congress 3D Cosi Dh Flatoptics is Pcaop Part of Imaging and Applied Optics Congress 2023 · January 1, 2023 We propose a simple yet powerful mask design for high-speed, high-pixel count compressive temporal imaging. Simulation and experimental results demonstrate a reconstruction quality of over 30dB when recovering 512 frames of 2K videos from a single snapshot ... Full text Cite

Target discrimination in the extended SWIR (eSWIR) band (2-2.5μm) compared to Vis, NIR, and SWIR in degraded visual environments

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2022 Long-range target identification is well studied in the Visible (Vis) and near-infrared (NIR) bands, and more recently in the shortwave infrared (SWIR). The longer wavelength of SWIR (1-1.7μm) improves target detection for both long ranges and under challe ... Full text Cite

Large area coverage using drone mounted multi-camera systems

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2022 The recent advancements in commercial drone performance and capability have seen their use in private industries proliferate. In terms of large area coverage, low-flying drones can accomplish the same tasks as larger unmanned aerial vehicles (UAVs) and sma ... Full text Cite

Array Camera Sampling Optimization

Conference Optics Infobase Conference Papers · January 1, 2022 We consider sampling system optimization in the context of deep-learning-based data fusion for dynamic high depth of field events, such as baseball. We show that multiscale spatio-spectral-focal-temporal sampling is ideal. ... Cite

Lens design for parallel super cameras

Conference 2022 Conference on Lasers and Electro Optics Pacific Rim CLEO PR 2022 Proceedings · January 1, 2022 For compact gigapixel-scale cameras, multiscale lens designs are needed, but recent array camera designs utilize discrete heterogenous arrays. This presentation reviews heterogenous array designs and discusses the motivation for this design choice. ... Full text Cite

Lens design for parallel super cameras

Conference International Conference on Optics Photonics Design and Fabrication Odf 2022 in Proceedings of the 2022 International Symposium on Imaging Sensing and Optical Memory Isom and the 13th International Conference on Optics Photonics Design and Fabrication Odf · January 1, 2022 For compact gigapixel-scale cameras, multiscale lens designs are needed, but recent array camera designs utilize discrete heterogenous arrays. This presentation reviews heterogenous array designs and discusses the motivation for this design choice. ... Cite

Optical Processing for Artificial Neural Vision

Conference 2021 Conference on Lasers and Electro-Optics, CLEO 2021 - Proceedings · May 1, 2021 Convolutional neural networks have become established as the primary mechanisms for image processing over the past decade. While general purpose optical neural networks remain a long term project, in the near term optical prefilters act as the first layers ... Cite

Optical Processing for Artificial Neural Vision

Conference 2021 Conference on Lasers and Electro Optics CLEO 2021 Proceedings · May 1, 2021 Convolutional neural networks have become established as the primary mechanisms for image processing over the past decade. While general purpose optical neural networks remain a long term project, in the near term optical prefilters act as the first layers ... Full text Cite

Optical processing for artificial neural vision

Conference Optics Infobase Conference Papers · January 1, 2021 Convolutional neural networks have become established as the primary mechanisms for image processing over the past decade. While general purpose optical neural networks remain a long term project, in the near term optical prefilters act as the first layers ... Cite

Image quality improvement in Fresnel zone aperture-based lensless camera with ptychography-inspired reconstruction

Conference Optics Infobase Conference Papers · January 1, 2021 To overcome the resolution and noise limits in Fresnel zone aperture-based lensless cameras, two types of multi-shot imaging are proposed. Simulated results show these methods successfully suppress the effect of sensor noise and diffraction. ... Cite

Panda: A gigapixel-level human-centric video dataset

Conference Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition · January 1, 2020 We present PANDA, the first gigaPixel-level humAN-centric viDeo dAtaset, for large-scale, long-term, and multi-object visual analysis. The videos in PANDA were captured by a gigapixel camera and cover real-world scenes with both wide field-of-view (∼1 km Full text Cite

Signal decoupling in digital holography via compressive sensing

Conference IEEE International Symposium on Industrial Electronics · June 1, 2019 Digital holography (DH) could realize three dimensional (3-D) imaging since it records the wavefront induced by an object volume. However, DH suffers from two inherent drawbacks for 3-D imaging: the twin images and cross talks between different depths. Bot ... Full text Cite

Compressive depth-resolved holographic microscope

Conference Proceedings Digital Holography and Three Dimensional Imaging 2019 · May 13, 2019 Holographic imaging suffers from twin images and cross-talks between different layers of three-dimensional objects even at millimeter scale. Compressive sensing associated with holographic microscope achieves micron level depth-resolved imaging free from t ... Full text Cite

Compressive depth-resolved holographic microscope

Conference Optics Infobase Conference Papers · May 13, 2019 Holographic imaging suffers from twin images and cross-talks between different layers of three-dimensional objects even at millimeter scale. Compressive sensing associated with holographic microscope achieves micron level depth-resolved imaging free from t ... Cite

Noise reduction in digital holography based on a filtering algorithm

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2018 Holography is a tool to record the object wavefront by interference. Complex amplitude of the object wave is coded into a two dimensional hologram. Unfortunately, the conjugate wave and background wave would also appear at the object plane during reconstru ... Full text Cite

Configurable cameras with MMS architecture

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2018 Monocentric multiscale (MMS) lens architecture provides a versatile, compact, high information efficiency and low-cost way of building panoramic imagers which can be easily tailored to various application scenarios. MMS lens consists of two parts, one conc ... Full text Cite

Multiscale gigapixel video: A cross resolution image matching and warping approach

Conference 2017 IEEE International Conference on Computational Photography Iccp 2017 Proceedings · June 16, 2017 We present a multi-scale camera array to capture and synthesize gigapixel videos in an efficient way. Our acquisition setup contains a reference camera with a short-focus lens to get a large field-of-view video and a number of unstructured long-focus camer ... Full text Cite

Parallel MMS gigapixel imagers

Conference Optics Infobase Conference Papers · January 1, 2017 We present a new architecture for monocentric multiscale (MMS) gigapixel imagers. This new architecture parallels multiple MMS imagers together to interleave a continuous wide field-of-view (FOV) coverage, resulting in a more compact system layout. ... Full text Cite

Resolution enhancement with a grating in lens-less digital holographic imaging

Conference Optics Infobase Conference Papers · January 1, 2017 The imaging resolution is enhanced with multiple diffraction orders from a grating in front of the sensor in lens-less digital holography. A 1024 × 1024 image is reconstructed from a 640 × 480 hologram with the proposed algorithm. ... Full text Cite

Recent advances in gigapixel cameras

Conference Optics Infobase Conference Papers · January 1, 2017 Continuing advances in computational architecture, optical design and software have reduced gigapixel camera system volume by more than two orders of magnitude and have also greatly advanced system utility. ... Full text Cite

Spectrally grouped total variation reconstruction for scatter imaging using ADMM

Conference 2015 IEEE Nuclear Science Symposium and Medical Imaging Conference NSS Mic 2015 · October 3, 2016 We consider X-ray coherent scatter imaging, where the goal is to reconstruct momentum transfer profiles (spectral distributions) at each spatial location from multiplexed measurements of scatter. Each material is characterized by a unique momentum transfer ... Full text Cite

Performance assessment of image translation-engineered point spread functions

Conference Optics Infobase Conference Papers · July 18, 2016 We demonstrate image translation, a general method for task-dependent point spread function engineering. Here, we compare the optical performance of variations of image translation with several well known imaging methods. © OSA 2016. ... Full text Cite

Gigapixel television

Conference Optics Infobase Conference Papers · July 18, 2016 We consider image capture and real-time rendering for virtual reality television. Array cameras enable multiuser digital pan, tilt, zoom and view point translation but require novel optical and electronic architectures. © OSA 2016. ... Full text Cite

CZT detector modeling for coded aperture X-ray diffraction imaging applications

Conference 2014 IEEE Nuclear Science Symposium and Medical Imaging Conference NSS Mic 2014 · March 10, 2016 CZT detectors are primary candidates for many next-generation X-ray diffraction imaging systems. We have conducted a study to evaluate performance tradeoffs and limitations of CZT energy-sensitive detectors in coded aperture X-ray imaging (CAXI) architectu ... Full text Cite

Coded aperture x-ray diffraction imaging with transmission computed tomography side-information

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2016 Coded aperture X-ray diffraction (coherent scatter spectral) imaging provides fast and dose-efficient measurements of the molecular structure of an object. The information provided is spatially-dependent and material-specific, and can be utilized in medica ... Full text Cite

Multi-view coded aperture coherent scatter tomography

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 We use coded apertures and multiple views to create a compressive coherent scatter computed tomography (CSCT) system. Compared with other CSCT systems, we reduce object dose and scan time. Previous work on coded aperture tomography resulted in a resolution ... Full text Cite

Snapshot full-volume coded aperture x-ray diffraction tomography

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 X-ray diffraction tomography (XRDT) is a well-established technique that makes it possible to identify the material composition of an object throughout its volume. We show that using coded apertures to structure the measured scatter signal gives rise to a ... Full text Cite

High precision, medium flux rate CZT spectroscopy for coherent scatter imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 CZT detectors are primary candidates for many next-generation X-ray imaging systems. These detectors are typically operated in either a high precision, low flux spectroscopy mode or a low precision, high flux photon counting mode. We demonstrate a new dete ... Full text Cite

Domain and range decomposition methods for coded aperture x-ray coherent scatter imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 Coded aperture X-ray coherent scatter imaging is a novel modality for ascertaining the molecular structure of an object. Measurements from different spatial locations and spectral channels in the object are multiplexed through a radiopaque material (coded ... Full text Cite

Impact of detector geometry for compressive fan beam snapshot coherent scatter imaging

Conference Proceedings of SPIE the International Society for Optical Engineering · January 1, 2016 Previous realizations of coded-aperture X-ray diffraction tomography (XRDT) techniques based on pencil beams image one line through an object via a single measurement but require raster scanning the object in multiple dimensions. Fan beam approaches are ab ... Full text Cite

Alternating minimization algorithm with iteratively reweighted quadratic penalties for compressive transmission tomography

Conference Progress in Biomedical Optics and Imaging Proceedings of SPIE · January 1, 2015 We propose an alternating minimization (AM) algorithm for estimating attenuation functions in X-ray transmission tomography using priors that promote sparsity in the pixel/voxel differences domain. As opposed to standard maximum-a-posteriori (MAP) estimati ... Full text Cite

Temporal compressive sensing for video

Conference · January 1, 2015 Video camera architects must design cameras capable of high-quality, dynamic event capture, while adhering to power and communications constraints. Though modern imagers are capable of both simultaneous spatial and temporal resolutions at micrometer and mi ... Full text Cite

Task-driven Adaptive Sensing on Quadrupole Mass Filter Systems for Classification

Conference Optics Infobase Conference Papers · January 1, 2015 An information-theoretical adaptive sensing and classification framework is proposed for Quadrupole mass filter systems. Simulation results demonstrate significant reduction in number of measurement and improvement of classification accuracy using the adap ... Cite

Coded Aperture Compressive Spectral-Temporal Imaging

Conference Optics Infobase Conference Papers · January 1, 2015 We present a compressive camera that combines mechanical translation and spectral dispersion to compress a multi-spectral, high-speed scene onto a monochrome, video-rate detector. Single-frame reconstructions of 15 spectral channels and 10 temporal frames ... Cite

W-band imager without mechanical scanning based on an echelle spectrometer

Conference International Conference on Infrared Millimeter and Terahertz Waves Irmmw Thz · November 13, 2014 We describe a two-dimensional imager in W-band using a single heterodyne transceiver and no mechanical scanning. By using an echelle grating spectrometer, frequencies are mapped onto a 2-D surface in space, so that spectral analysis of the signals provides ... Full text Cite

Gigapixel whole-body microphotography

Conference Frontiers in Optics, FiO 2014 · October 14, 2014 Time-series whole-body microphotography may potentially be used for diagnosing skin disease, telemedicine, surgical field registration, and epidemiological studies. We demonstrate the technology by imaging a volunteer at 0.25 gigapixel resolution in a snap ... Cite

Gigapixel whole-body microphotography

Conference Frontiers in Optics Fio 2014 · October 14, 2014 Time-series whole-body microphotography may potentially be used for diagnosing skin disease, telemedicine, surgical field registration, and epidemiological studies. We demonstrate the technology by imaging a volunteer at 0.25 gigapixel resolution in a snap ... Full text Cite

Low-cost compressive sensing for color video and depth

Conference Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition · September 24, 2014 A simple and inexpensive (low-power and low-bandwidth) modification is made to a conventional off-the-shelf color video camera, from which we recover multiple color frames for each of the original measured frames, and each of the recovered frames can be fo ... Full text Cite

Compressive millimeter wave and X-ray tomography

Conference Optics Infobase Conference Papers · January 1, 2014 Compressive tomography consists of estimation of high dimensional objects from measurements distributed over lower dimensions. Examples include reconstruction of 3D spectral data cubes from 2D focal planes and reconstruction of 3D volumes from 2D x-ray pro ... Full text Cite

Roadmap for commercial gigapixel cameras

Conference Optics Infobase Conference Papers · January 1, 2014 Multiscale array cameras allow 10-100x improvements in commercial camera resolution. This talk discussed the optical manufacturing, electronic processing and communications and cloud software ecosystem that enables economical multiscale cameras. © 2014 OSA ... Full text Cite

Simulations of 2D metamaterial apertures for coherent computational imaging

Conference 2013 IEEE International Conference on Microwaves Communications Antennas and Electronic Systems Comcas 2013 · December 1, 2013 A metamaterial aperture operating as a leaky waveguide with resonating metamaterial irises can sweep its operation frequency to modify its complex field pattern with no moving parts. By randomly distributing the metamaterials' resonance frequencies, we sho ... Full text Cite

Alignment and assembly strategies for AWARE-10 gigapixel-scale cameras

Conference OPTOMECHANICAL ENGINEERING 2013 · 2013 Full text Link to item Cite

Coded aperture snapshot spectral imager based on liquid crystal spatial light modulator

Conference Optics Infobase Conference Papers · January 1, 2013 We describe the use of a liquid crystal on silicon modulator to jointly code spatial and spectral features for snapshot spectral imaging. We demonstrate compressive measurement of megapixel multispectral image with 5 nm resolution. © OSA 2013. ... Full text Cite

Adaptive scanning for synthetic aperture imagers

Conference Optics Infobase Conference Papers · January 1, 2013 Synthetic aperture imagers measure the space-bandwidth product of full-apertures by moving a single detector. We show results from an adaptive sensing experiment that demonstrate a three times speedup over full-scans. © 2013 Optical Society of America. ... Full text Cite

Multiscale, dictionary-based speckle denoising

Conference Optics Infobase Conference Papers · January 1, 2013 We propose a multiscale, dictionary-based, data-adaptive estimation method to recover intensities from multiplicative, speckle data. The proposed method preserves the edges and textures in the underlying image while smoothing intensities in homogenous regi ... Full text Cite

A wide-field catadioptric monocentric multiscale telescope with all-spherical glass optics

Conference Optics Infobase Conference Papers · January 1, 2013 Monocentric multiscale design combines a common objective optic with an array of secondary apertures to enable wide field of view high resolution imaging. Here we describe a 15o field of view with 1.1 arcsecond ifov. © OSA 2013. ... Full text Cite

Efficient model-based tonemapping of high dynamic range gigapixel images

Conference Optics Infobase Conference Papers · January 1, 2013 We present a technique to address the tonemapping of high dynamic range (HDR) gigapixel images. The proposed method relies on extracting low-dimensional models from lowresolution proxy images, and can be efficiently implemented in a parallel manner. © OSA ... Full text Cite

Color image formation for multiscale gigapixel imaging

Conference Optics Infobase Conference Papers · January 1, 2013 We present the current development of the image formation pipeline for color gigapixel images obtained by the AWARE-10 multiscale camera.We introduce a camera simulator, the modifications to the scalable pipeline, and the challenges for creating seamless c ... Full text Cite

Compressive sensing for video using a passive coding element

Conference Optics Infobase Conference Papers · January 1, 2013 We present a prototype system that utilizes mechanical translation of a passive coding element to compress high-speed temporal information into low-framerate video sequences. Reconstructions of 148 frames per experimental coded snapshot are reported. © OSA ... Full text Cite

Coding for X-ray scatter imaging

Conference Optics Infobase Conference Papers · January 1, 2013 We present coding strategies for x-ray scatter imaging, with focus on pencil and fan beam geometries. Coded apertures spatially modulate the scatter signal prior to measurement, and appropriate reconstruction algorithms recover the tomographic images. © OS ... Full text Cite

Compressive tomography

Conference Optics Infobase Conference Papers · January 1, 2013 Dimension-reducing transformations in geometric, diffractive and coherence tomography may be coded to improve image acquisition rate, resolution and feature specificity. We consider example coding strategies for snapshot (scan-free) tomography in x-ray, di ... Full text Cite

Image formation in multiscale optical systems

Conference Optics InfoBase Conference Papers · January 1, 2011 We present image formation (IF) strategies developed for multiscale imaging systems. In this context, IF takes advantage of significant prior knowledge of array geometry and relies on parallelizable algorithms to handle the high data bandwidth. © 2011 OSA. ... Cite

A multiscale, wide field, gigapixel camera

Conference Optics InfoBase Conference Papers · January 1, 2011 Recent investigations into high pixel count imaging using multiscale optics have led to a novel optical design for a wide field, gigapixel camera. We review the mechanical design and optical performance of this imager. © 2011 OSA. ... Cite

Optimizing microcamera aperture in gigapixel monocentric multiscale cameras

Conference Optics InfoBase Conference Papers · January 1, 2011 Multiscale designs divide the imaging task between a simple objective and many complex microcameras. We study imaging quality as the microcamera aperture size varies from 0.375 to 36 mm with 2 and 50 gigapixel objectives. © 2011 Optical Society of America. ... Cite

A multiscale, wide field, gigapixel camera

Conference Optics Infobase Conference Papers · January 1, 2011 Recent investigations into high pixel count imaging using multiscale optics have led to a novel optical design for a wide field, gigapixel camera. We review the mechanical design and optical performance of this imager. © 2011 OSA. ... Full text Cite

Joint segmentation and reconstruction of coded aperture hyperspectral data

Conference Optics Infobase Conference Papers · January 1, 2011 This work presents experimental verification of a joint segmentation reconstruc- tion algorithm on real data from a snapshot hyperspectral imager. Accurate spectra can be computed for any pixel location in the data cube. © 2011 Optical Society of America. ... Full text Cite

Optimizing microcamera aperture in gigapixel monocentric multiscale cameras

Conference Optics Infobase Conference Papers · January 1, 2011 Multiscale designs divide the imaging task between a simple objective and many complex microcameras. We study imaging quality as the microcamera aperture size varies from 0.375 to 36 mm with 2 and 50 gigapixel objectives. © 2011 Optical Society of America. ... Full text Cite

Gigagon: A monocentric lens design imaging 40 gigapixels

Conference Optics Infobase Conference Papers · January 1, 2010 The Gigagon is a f/2.5 five element monocentric lens resolving under 2 arcsec over a 120 degree field of view intended to image onto megapixel sensors tiled over the focal surface. © 2010 Optical Society of America. ... Cite

Integrated nano-hole array surface plasmon resonance biochemical sensor

Conference Optics Infobase Conference Papers · January 1, 2010 We have demonstrated a super-periodic metallic nano-hole array surface plasmon device for integrated biochemical sensing. The super-periodic nano-hole array device combines functions of sensing and surface plasmon resonance spectral analysis on a single de ... Full text Cite

Sparse fourier sampling in millimeter-wave compressive holography

Conference Optics Infobase Conference Papers · January 1, 2010 We analyze the impact of sparse sampling on millimeter-wave (MMW) two-dimensional (2D) holographic measurements for three-dimensional (3D) object reconstruction. Simulations address 3D object estimation efficacy. We present 3D object reconstructions from e ... Full text Cite

Multiscale optical systems

Conference Optics Infobase Conference Papers · January 1, 2009 Cameras capturing gigapixel or even terapixel images are enabled by lens systems combining single aperture objectives with arrays of smaller scale processing optics. © 2009 Optical Society of America. ... Full text Cite

Coding and signal inference in compressive holography

Conference Optics Infobase Conference Papers · January 1, 2009 Compressive sensing enables highly accurate signal reconstruction from fewer measurements than the number of samples in a signal to be estimated. This paper describes a theoretical framework for 3D tomographic reconstruction from 2D holographic measurement ... Full text Cite

Millimeter-wave imaging using k-space compression

Conference Optics Infobase Conference Papers · January 1, 2009 We apply compression in the spatial frequency domain to generate millimeter wave images. Simulations indicate the efficacy of the approach. We are in the process of testing the system experimentally. © 2009 Optical Society of America. ... Full text Cite

Aberration correction in multiscale lenses

Conference Optics Infobase Conference Papers · January 1, 2009 Multiscale lens design splits the field into subregions and attempts to correct the local wavefront error in each subfield rather than the global error. We review the aberration theory underlying the approach. © 2009 Optical Society of America. ... Full text Cite

Experimental demonstrations of compressive holography

Conference Optics Infobase Conference Papers · January 1, 2009 We demonstrate 3D object reconstruction from a single 2D data plane using compressive holography in Gabor and Leith-Upatneiks geometries. © 2009 Optical Society of America. ... Full text Cite

Quantitative performance metrics with long wave infrared multiple aperture cameras

Conference Optics Infobase Conference Papers · January 1, 2008 We characterize a long wave infrared multiple aperture imaging system by experimentally measuring its Noise Equivalent Temperature Difference and modulation transfer function. These results are compared with a conventional system. © 2008 Optical Society of ... Full text Cite

Resolving wall ambiguities using angular diverse synthetic arrays

Conference IEEE International Conference on Neural Networks Conference Proceedings · December 1, 2007 Model-based algorithms that attempt to localize targets and estimate the structure within a building using data from external sensors have received much attention in recent years. The potential benefits to homeland security and urban warfare are exceedingl ... Full text Cite

Dynamic logic applied to SAR data for parameter estimation behind walls

Conference IEEE National Radar Conference Proceedings · September 27, 2007 Identifying and localizing targets within buildings using exterior sensors will offer superior advantages to the military and law enforcement communities. Research on wall-penetrating radar has produced significant advances in recent years regarding this t ... Full text Cite

Compressive spectral imaging and multiscale reconstruction methods

Conference Optics InfoBase Conference Papers · January 1, 2007 In this work we develop a single-shot, dual-disperser spectral imaging system and associated multiscale photon-limited multispectral reconstruction methods that have been designed to exploit the emerging theory of compressive sensing. © 2007 Optical Societ ... Cite

An ultra-high resolution volume holographic spectrometer

Conference Optics Infobase Conference Papers · January 1, 2007 We have designed a compact spectrometer by cascading a simple Fabry-Perot etalon and a cylindrical beam volume hologram. The combination of these two elements results in a twodimensional spatial-spectral mapping in the output plane. Using this spectrometer ... Full text Cite

Multidimensional spatial and coherence imaging using single shot spectral imagers

Conference Optics Infobase Conference Papers · January 1, 2007 A spectral imaging system may efficiently sense 10-100 spectral channels but the full data cube is often redundant. We propose to exploit this redundancy to computationally expand depth of field or obtain multidimensional spatial images. © 2007 Optical Soc ... Full text Cite

Compressive measurements for video

Conference Optics Infobase Conference Papers · January 1, 2007 Redundancies present in video streams could be used to implement compressive sampling to achieve low power video sensors. We explore the possibilities of using this in the design of compressive video sensors and corresponding algorithms. © 2007 Optical Soc ... Full text Cite

Compressive spectral imaging and multiscale reconstruction methods

Conference Optics Infobase Conference Papers · January 1, 2007 In this work we develop a single-shot, dual-disperser spectral imaging system and associated multiscale photon-limited multispectral reconstruction methods that have been designed to exploit the emerging theory of compressive sensing. © 2007 Optical Societ ... Full text Cite

The MONTAGE least gradient image reconstruction

Conference Optics Infobase Conference Papers · January 1, 2007 We introduce an image reconstruction algorithm for the Compressive Optical MONTAGE Photography Initiative, for recovering the resolution of an image from a set of aliased subimages acquired by a lenslet array optical system. © 2007 Optical Society of Ameri ... Full text Cite

Depth of field with multi-aperture LWIR imagers

Conference Optics Infobase Conference Papers · January 1, 2007 We use a multiaperture approach to design a thin LWIR camera. Having a shorter focal length, the microlens array provides an extended depth of field over the conventional system. © 2007 Optical Society of America. ... Full text Cite

An ultra-high resolution tandem fabry-perot etalon cylindrical beam volume hologram spectrometer

Coded-excitation Raman spectroscopy for Raman signal estimation in highly fluorescent media

Conference Optics Infobase Conference Papers · January 1, 2007 Raman signal estimation in highly fluorescent media is investigated using multiple excitation lasers and an iterative EM spectral reconstruction algorithm. Results from an 8-laser system show estimation performance increases with the number of excitation l ... Full text Cite

Multiplexed point spread functions for image formation with application to large area sensing and surveillance

Conference Optics Infobase Conference Papers · January 1, 2007 Full text Cite

Integrated sensing and processing of Raman spectra for in vivo BAC measurement

Conference ALCOHOLISM-CLINICAL AND EXPERIMENTAL RESEARCH · June 1, 2006 Link to item Cite

Super-resolution mapping of flow velocity distribution in nanofluidic channels

Conference Optics Infobase Conference Papers · January 1, 2006 We will show a super-resolution mapping technique for measuring the flow velocity distribution in nanofluidic channels. The mapping resolution can be much smaller than the diffraction limit of the optical imaging system. © 2006 Optical Society of America. ... Full text Cite

Coded-excitation Raman spectroscopy for ethanol chemometrics of tissue

Conference Optics Infobase Conference Papers · January 1, 2006 Raman spectroscopy of bulk tissue is challenging due to sample auto-fluorescence and weak Raman cross-sections of most molecules. We investigate the use of coded-excitation Raman spectroscopy coupled with an iterative algorithm for Raman signal estimation. ... Full text Cite

Ultra-thin multi-aperture LWIR imagers

Conference Optics Infobase Conference Papers · January 1, 2006 We design and implement an ultra-thin LWIR camera by replacing the conventional lens system with a micro-lens array. The resulting low resolution images can be used to reconstruct a high resolution image by post processing. © 2006 Optical Society of Americ ... Full text Cite

A compact Fabry-Perot grating cascaded spectrometer

Conference Optics Infobase Conference Papers · January 1, 2006 We have designed a compact spectrometer by cascading a simple Fabry-Perot etalon and a grating. The grating expands the limited spectral range of the Fabry-Perot and the combination of both elements results in a powerful spectrometer with good two-dimensio ... Full text Cite

Compressive sampling in spectral imaging systems

Conference Optics Infobase Conference Papers · January 1, 2006 Optical prefilters shape the analog-digital interface in imaging systems to implement generalized spatio-spectral sampling. The Duke Imaging and Spectroscopy Program explores generalized sampling systems, this talk focuses specifically on spectral encoding ... Full text Cite

Super-resolution Mapping of Flow Velocity Distribution in Nanofluidic Channels

A Compact Fabry-Perot Grating Cascaded Spectrometer

Longwave Infrared (LWIR) Coded Aperture Dispersive Spectrometer

Conference Optics Infobase Conference Papers · January 1, 2006 We describe a static aperture-coded, dispersive longwave infrared (LWIR) spectrometer that uses a microbolometer array as the detector plane. We present experimental results of absorption spectroscopy for a variety of sources. ... Cite

Using Cramér-Rao theory for multiple agents

Conference 2005 International Conference on Integration of Knowledge Intensive Multi Agent Systems Kimas 05 Modeling Exploration and Engineering · December 1, 2005 This paper develops Cramér-Rao theory for multi-agent system design. We apply Cramér-Rao theory to synthetic aperture radar (SAR) in order to establish optimal performance bounds that are independent from signal processing algorithms. Bounds on the estimat ... Full text Cite

Using Cramér-Rao theory for SAR waveform design

Conference IEEE National Radar Conference Proceedings · January 1, 2005 This paper applies Cramér-Rao theory to synthetic aperture radar (SAR) in order to establish optimal performance bounds on target parameter estimation. The Cramér-Rao bound (CRB) establishes a lower bound on the error variance of unbiased or asymptotically ... Full text Cite

Diffractive generation of non-redundant images for a multi-aperture, thin, high-resolution camera

Conference Optics Infobase Conference Papers · January 1, 2005 We have designed a diffractive element capable of generating shift-encoded images for a thin, multiplexed optical imaging system. We present simulations that validate the use of the element for high resolution imaging and preliminary experimental results o ... Full text Cite

Diffraction-limited impulse response image reconstruction with a single imaging pixel

Conference Optics Infobase Conference Papers · January 1, 2005 In this paper, we will discuss two techniques to reconstruct diffraction-limited impulse response images by sub-pixel shifting the photodetector array and measuring the signal from a specific large area photodetector pixel. © 2005 Optical Society of Americ ... Full text Cite

Large area pyroelectric motion tracking system

Conference Optics Infobase Conference Papers · January 1, 2005 Simple pyroelectric detectors and structured apertures are used to monitor motion in an area and report location and velocity of objects moving through the monitored area. © 2005 OSA/COSI 2005. ... Full text Cite

Multimodal, multiplex Raman spectrometer for weak, incoherent sources

Conference Optics Infobase Conference Papers · January 1, 2005 Raman spectroscopy in bio-materials is complicated by fluorescence and scattering. We have developed a multimodal, multiplex spectrometer that overcomes these difficulties. We are currently constructing a second generation prototype for in-vivo Raman spect ... Full text Cite

Compressive sampling for feature specific compact imagers

Conference Optics Infobase Conference Papers · January 1, 2005 We investigate the use of estimation methods with multi-aperture imaging hardware that are noise robust and able to provide high resolution images from limited measurements. © 2005 Optical Society of America. ... Full text Cite

Multi-aperture visible high resolution thin imager

Conference Optics Infobase Conference Papers · January 1, 2005 We have designed and built a multi-aperture thin imager using a lenslet array and a CCD imager. The thickness of the imager is significantly reduced. We will present experimental results that demonstrate high resolution imaging. © 2005 Optical Society of A ... Full text Cite

The quantized cosine transform for sensor-layer image compression

Conference Optics Infobase Conference Papers · January 1, 2005 We introduce a compressive encoding at the sensor layer based on the quantized cosine transform. Compression at the physical layer of integrated imaging systems reduces the measurements-to-pixels ratio, the data volume and accelerates image estimation. © 2 ... Full text Cite

Compact spectral diversity filters for diffuse source spectroscopy using spherical beam volume holograms

Conference Optics Infobase Conference Papers · January 1, 2005 We describe a new class of compact spectral diversity filters implemented using spherical beam volume holograms. Spectral diversity is improved by rotation multiplexing technique. Diffuse source spectroscopy enabled by using Fourier transform architecture ... Full text Cite

Compressive optical MONTAGE photography initiative: Noise and error analysis

Conference Optics Infobase Conference Papers · January 1, 2005 Image resolution is usually considered to be proportional to the focal plane sampling rate. However, as a result of Papoulis's generalized sampling theory [1], it is possible to reconstruct bandlimited images from sub-Nyquist sampled data provided multiple ... Full text Cite

Multiplex design for high-performance microspectrometers

Conference Optics Infobase Conference Papers · January 1, 2005 The volume of spectrometers can be drastically reduced through the use of multiplex measurement. Reductions of 3-5 orders of magnitude are possible. This has the potential to drastically effect manufacturing and deployment costs. ©2005 Optical Society of A ... Full text Cite

Human motion tracking system using coded Fresnel lens arrays

Conference Optics Infobase Conference Papers · January 1, 2005 We have designed and developed a low-cost human motion tracking system using pyroelectric detectors and coded Fresnel lens arrays. We have deployed sensor clusters implementing an 8x8 Hadamard code variant and will demonstrate motion tracking. © 2005 Optic ... Full text Cite

Design of a thin multi-aperture infrared imager

Conference Optics Infobase Conference Papers · January 1, 2005 We have designed a thin, multiplexed infrared imaging system that uses a diffractive element for generating shift-encoded images in each aperture. We present preliminary experimental results that demonstrate imager performance. © 2005 Optical Society of Am ... Full text Cite

Super-resolved point source tracking using birefringent impulse response coding

Conference Proceedings of the 8th Joint Conference on Information Sciences, Vols 1-3 · January 1, 2005 Link to item Cite

Coded-aperture, multi-wavelength Raman spectroscopy for ethanol detection in biological samples

Conference Proceedings of the 8th Joint Conference on Information Sciences, Vols 1-3 · January 1, 2005 Link to item Cite

Phenomenology-based waveform design using Cramer-Rao theory

Conference 2004 International Waveform Diversity and Design Conference Wdd 2004 Proceedings · July 2, 2004 The Cramer Rao Bound (CRB) establishes a lower bound on the error variance of an unbiased parameter estimate [5]. We have derived CRBs for target parameter estimates using synthetic aperture radar (SAR), and allow for spatial waveform diversity. The first ... Full text Cite

Bounds on range-resolution degradation using RSSI measurements

Conference IEEE International Conference on Communications · January 1, 2004 In this paper, we investigate the fundamental loss of ranging resolution using received signal strength indicator (RSSI) observations relative to unprocessed received signal (URS) measurements. Unlike previous work, this is done for a single propagation mo ... Full text Cite

Static, multimodal, multiplex spectrometer design for weak, incoherent sources

Conference Optics Infobase Conference Papers · January 1, 2004 We present a flexible design for a static, multimodal, multiplex spectrometer which is optimized for the weak incoherent sources that are common in biomedical applications. Simultaneous high throughput and resolution are achieved in a single-shot measureme ... Cite

Modeling and Experimental Characterizing the Filter Function of Holographic Spectral Diversity Filters for Multimodal Multiplex Spectroscopy

Conference Optics Infobase Conference Papers · January 1, 2004 We propose an analytical solution based on Born-approximation for diffraction analysis of relatively strong multiplexed holograms. The direct application of this method is designing holograms for multimodal multiplex spectroscopy (MMS) applications. The fi ... Cite

Implementation of Efficient Fourier-transform Holographic Spectrometer

Conference Optics Infobase Conference Papers · January 1, 2004 We present the first implementation of a Fourier-transform spherical beam holographic spectrometer with considerably better sensitivity compared to conventional grating spectrometers. We use this idea to demonstrate a compact spectrometer that is usually e ... Cite

Multimodal, multiplex Raman spectrometry for detection of ethanol in blood and tissue

Conference Optics Infobase Conference Papers · January 1, 2004 We investigate the application of static, multimodal, multiplex spectrometers to the detection of the Raman spectrum of ethanol in blood and tissue. These spectrometers are optimized for use with weak, incoherent sources, and enable relatively high sensiti ... Cite

Fiber optical web for object localization by geometric space coding

Conference Optics Infobase Conference Papers · January 1, 2004 A fiber web was used for object(s) localization. The fiber web used binary codes to segment and encode the object space. We employed 2D gray code to localize an extended object and superimposed code to localize multiple objects simultaneously. Experimental ... Cite

Visibility modulation using Reference Structures for human motion tracking

Conference Optics Infobase Conference Papers · January 1, 2004 Cite

Bounds on wireless location estimation of mobile transmitters in a time varying acoustic underwater channel

Conference Oceans Conference Record IEEE · December 1, 2003 Wireless localization of multiple mobile underwater transmitters becmae a very important area of research. Several solutions to the underwater localization problem consider the measurement of the first time of arrival of a signal coming from a node with un ... Cite

Design and analysis of photonic crystal spectral diversity filters for biosensing

Conference Optics Infobase Conference Papers · January 1, 2003 Cite

Efficient motion sensing system using pyroelectric sensors

Conference Optics Infobase Conference Papers · January 1, 2003 We describe a motion sensor system that can discriminate 'N' source states using logarithm of 'N' sensor measurements. Based on this design approach, we implement a motion sensing system using pyroelectric sensors as the sensing element and a reference str ... Cite

Three dimensional imaging using reference structures

Conference Optics Infobase Conference Papers · January 1, 2003 We describe an imaging system based on a novel volume optical element, a tomographic reference structure, which implements a mapping from a three dimensional source volume on to a two dimensional sensor plane. We show how reference structures spatially seg ... Cite

Accurate design and analysis of spherical beam volume holograms for sensing applications

Conference Optics Infobase Conference Papers · January 1, 2003 We present an accurate model for design and analysis of volume holograms recorded by spherical reference beams. We explain how it can be used for analysis of incoherent Raman signals in bio and environmental sensing. For such applications, conventional mod ... Cite

Differential tracking system by geometrical segmentation of source space with coded laser beams

Conference Optics Infobase Conference Papers · January 1, 2003 We describe a differential tracking system (DTS) based on differential pulse code modulation channel. A laser beam web is employed to segment and differentiate the source space and measure the quantized source velocity vector. DTS can track a source in N p ... Cite

3D spatial segmentation using reference structures

Conference Optics Infobase Conference Papers · January 1, 2003 We describe a sensor system based on 3D 'reference structures' which implements a mapping from a 3D source volume on to a 2D sensor plane. We consider examples of a few reference structures and how they spatially segment a 3D source volume and present some ... Cite

Target estimation from interferometric tracking telescopes

Conference Optics Infobase Conference Papers · January 1, 2003 Joint target triangulation and estimation from spatio-spectral tracking using a rotational shear interferometer on a telescope is described. The system is based on an array of three eight inch off-axis parabolic reflector telescopes with CCD cameras used f ... Cite

3D Optical Elements for Computational Sensors

Conference Optics Infobase Conference Papers · January 1, 2003 3D Optical Elements for Computational Sensors. We discuss geometric segmentation of optical fields by volume optical elements and 3D photonic circuits and describe example systems. 3D elements include volume holograms, geometric filters and microcavity arr ... Cite

Information flow in streaming 3D video

Conference Proceedings of SPIE the International Society for Optical Engineering · February 28, 2001 We describe streaming 3D video on the Argus sensor space. Argus is a Beowulf-style distributed computer with 64 processors and 64 video camera/capture pairs. Argus is a test-bed for comparing sensor space modeling and reconstruction algorithms. We describe ... Full text Cite

Three-dimensional coherence imaging in the Fresnel domain

Conference Optics Infobase Conference Papers · January 1, 2001 We show that three-dimensional incoherent primary sources can be reconstructed from finite-aperture Fresnel-zone mutual intensity measurements by means of coordinate and Fourier transformation. The spatial bandpass and impulse response for three-dimensiona ... Cite

Insights from the development of two generations of networked sensor and processor systems

Conference Optics Infobase Conference Papers · January 1, 2001 A wirelessly networked array of integrated sensor and processing modules has demonstrated video-rate tomographic reconstruction previously shown on a video enabled supercomputer cluster. We discuss issues regarding design and development of these first- an ... Cite

Spatio-spectral triangulation using a rotational shear interferometer

Conference Optics Infobase Conference Papers · January 1, 2001 We use a rotational shearing interferometer to determine the angular location and wavelength of sparse point sources by capturing 2 interference patterns on a CCD array. We demonstrate this using a portable RSI with embedded processing. ... Cite

Spatial tomography and coherence microscopy

Conference Optics Infobase Conference Papers · January 1, 2001 We describe a methodology for integrated computational imaging system design based on source specification, cross-spectral transformations and tomography. We consider design examples based on local and nonlocal measures of incoherent primary sources. ... Cite

Sensor plane processing for multiplex imaging

Conference 2000 Southwest Symposium on Mixed Signal Design Ssmsd 2000 · January 1, 2000 Digital imaging systems are fundamentally different from analog ones because they differentiate the measurement space and the reconstruction space. Multiplex systems use this separation to optimize source reconstruction. We consider the requirements impose ... Full text Cite

Optical detection of molecular beacons in microfluidic devices

Conference 1st Annual International IEEE EMBS Special Topic Conference on Microtechnologies in Medicine and Biology Proceedings · January 1, 2000 Hybridization and detection of E. coli ribosomal RNA with molecular beacons labeled with a fluorescent dye Is achieved in a microfluidic device. The device consists of a four ports mixing chamber, where the probes and the target molecules mix by diffusion. ... Full text Cite

Spectral spatial equalization for OFDM in time-varying frequency-selective multipath channels

Conference Proceedings of the IEEE Sensor Array and Multichannel Signal Processing Workshop · January 1, 2000 Orthogonal frequency division multiplex (OFDM) transmission over a time-variant frequency-selective multipath fading channel suffers from significant attenuation on faded frequency regions as well as inter-channel interference (ICI) due to the loss of subc ... Full text Cite

Restricted total least squares solutions for hyperspectral imagery

Conference ICASSP IEEE International Conference on Acoustics Speech and Signal Processing Proceedings · January 1, 2000 Hyperspectral image processing is a pixel-by-pixel approach to the detection and localization of features by spectral analysis techniques. Usually, partial knowledge about the feature, noise, and clutter spectra are provided, and the problem is to 'unmix' ... Full text Cite

Diffractive and Micro-Optics for Multiplex Imaging

Conference Optics Infobase Conference Papers · January 1, 2000 Multiplex systems require complex field encoding but are not particularly sensitive to discontinuity or chromatic dispersion. Diffractive and micro-optics provide a complex design space but have scattering and dispersion problems. This is a match made in h ... Cite

Confocal microscopy without pinhole

Conference Optics Infobase Conference Papers · January 1, 1999 Confocal microscopes achieve depth resolution by use of a pinhole. On-axis, in-focus point-source objects are imaged exactly inside the pinhole, and give maximal intensity. Out-of-focus objects, even on-axis, produce extended (blurred) images, and are filt ... Cite

Coherence-based Hybrid Optical/Computational Approaches to Three-dimensional Incoherent Imaging

Conference Optics Infobase Conference Papers · January 1, 1999 Cite

Superresolved imaging architectures with volume holograms

Conference Optics Infobase Conference Papers · January 1, 1999 Cite

Adaptive equalization for underwater wireless communications

Conference ICASSP IEEE International Conference on Acoustics Speech and Signal Processing Proceedings · January 1, 1996 Wireless acoustic communications through the underwater channel presents many challenges. On one hand, the channel is often characterized by an extended time-varying multipath structure spanning a hundred or more symbols, limited channel coherence times, a ... Cite

Sparse equalization for real-time digital underwater acoustic communications

Conference Oceans Conference Record IEEE · December 1, 1995 Due to the very long reverberation time of many ocean channels, the size of the adaptive filters required for conventional equalization becomes large, rendering the computational complexity of the adaptive receiver unacceptable for many cases of practical ... Cite

Reducing the computational requirements of adaptive equalization in underwater acoustic communications

Conference Oceans Conference Record IEEE · December 1, 1995 A key component in coherent underwater acoustic communication systems is an adaptive equalizer capable of tracking changes in the acoustic environment. The computation requirements of this equalizer can be very high, requiring substantial computation hardw ... Cite

Asymptotic coding gains in multiuser systems

Conference IEEE Vehicular Technology Conference · January 1, 1995 In this work the asymptotic multiuser coding gain (AMCG) as well as asymptotic multiuser efficiency (AME) are found for K coded asynchronous users and a variety of multiuser detectors, including optimum (MLS), multistage, decorrelated and conventional dete ... Cite

Characterization of waveguide and grating formation in As2S3

Conference IEEE LEOS Annual Meeting Proceedings · December 1, 1994 Photodarkening in the chalcogenide glass As2S3 makes it attractive for applications in integrated optics and data storage Various optical devices can be fabricated using the laser-induced change of refractive index in this material. W ... Cite

Throughput performance of multiuser detection in unslotted contention channels

Conference IEEE International Symposium on Information Theory Proceedings · December 1, 1994 In this work we analyze the throughput of a centralized packet receiver which utilizes multiuser detection in an unslotted contention channel. The receiver is capable of demodulating all overlapping, unit-length packets, provided that the T-length packet h ... Cite

Complexity-constrained LS estimation for sparse systems

Conference IEEE International Symposium on Information Theory Proceedings · December 1, 1994 The Sparse RLS (SRLS) algorithm, suitable for large-order sparse channels, chooses to update a subset of taps which will minimize the computational complexity of the algorithm given the constraint of maximum allowable increases in Mean Squared Error (MSE). ... Cite

Reduced-complexity RLS estimation for shallow-water channels

Conference IEEE Sympsium on Autonomous Underwater Vehicle Technology · December 1, 1994 An adjustable complexity, recursive least squares (RLS) estimation algorithm is presented, which is suitable for adaptive equalization and source localization in shallow-water acoustic channels. The algorithm adjusts its computational complexity, measured ... Cite

Adaptive multiuser receivers with diversity reception for nonselective Rayleigh fading asynchronous CDMA channels

Conference IEEE MILCOM · December 1, 1994 We investigate the performance of low-complexity decor-relating multiuser receivers with diversity reception in frequency-nonselective Rayleigh fading asynchronous CDMA channels. The impact of fading dynamics on the differentially coherent receivers with e ... Cite

Narrowband waveform design for near-far resistant asynchronous CDMA communications

Conference IEEE MILCOM · December 1, 1994 A technique to design narrowband signature waveforms for asynchronous code-division multiple-access (CDMA) systems is proposed. These waveforms are specially tailored for a class of near-far resistant multiuser detectors. They are strictly time-limited, sa ... Cite

Throughput performance of multiuser detection in unslotted contention channels

Conference Proceedings IEEE INFOCOM · December 1, 1994 The throughput of a centralized packet receiver capable of demodulating all overlapping unit-length packets provided that T-length packet headers do not overlap but K packets overlap at any one time, is analyzed. Violating one of the stated conditions sugg ... Cite

Complexity-constrained LS estimation for sparse systems

Conference IEEE International Symposium on Information Theory Proceedings · January 1, 1994 In an increasing number of applications the complexity of so-called fast RLS algorithms is prohibitive for real-time RLS estimation. One notable example is the adaptive equalization problem for intersymbol interference channels, where the number of equaliz ... Full text Cite

Adaptive multiuser detection in dispersive channels with array observations

Conference Conference Record Asilomar Conference on Signals Systems and Computers · January 1, 1994 We present a multiuser receiver which is capable of operating in time-variant channels with severe multipath. For each active user, the receiver consists of a multi-input, single-output filter followed by a single-user adaptive equalizer. The array process ... Full text Cite

Asymptotic multiuser efficiency of two-stage detection in mismatched AWGN channels

Conference Proceedings IEEE Military Communications Conference · December 1, 1993 In this paper we investigate the loss of near-far resistance for two multiuser detectors due to imperfect channel estimation in the additive white Gaussian noise multiple access channel. The symbol error rates and the Asymptotic Multiuser Efficiencies (AME ... Cite

Adaptive equalization techniques for interference suppression in shallow water acoustic telemetry channels

Conference Conference Record of the Asilomar Conference of Signals Systems Computers · December 1, 1993 Despite the severe propagation conditions in shallow water acoustic telemetry channels, coherent high-speed data transmission may be established using adaptive receivers based on a decision feedback equalizer (DFE) structure. The performance of a DFE in sh ... Cite

Asymptotic multiuser efficiency for 2-stage detectors in AWGN channels

Conference Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 In the AWGN multiple-access channel with binary phase-shift keying modulation, the kth user error probability for a given demodulator vanishes exponentially with the noise level as -ηk SNRk/2, where ηk is the asy ... Cite

Comparison of differentially coherent and coherent multiuser detection with imperfect phase estimates in a Rayleigh fading channel

Conference Proceedings of the 1993 IEEE International Symposium on Information Theory · January 1, 1993 Multiuser detectors have superior performance over their single-user counterparts in a multiple-access channel, assuming perfect knowledge of system parameters. In this paper we extend the analysis of multiuser detectors in fading channels by incorporating ... Cite

Volume holographic data storage in photo-organic media

Conference Conference Digest Joint International Symposium on Optical Memory and Optical Data Storage Omods 1993 · January 1, 1993 Full text Cite

Integrated Optical Pulse Shaping

Conference Optics Infobase Conference Papers · January 1, 1993 Cite

Multiple Wavelength Operation of a Diode Array Coupled to an External Cavity

Conference Optics Infobase Conference Papers · January 1, 1993 Cite

An adaptive, soft-decision multiuser receiver for underwater acoustical channels

Conference Conference Record Asilomar Conference on Signals Systems and Computers · January 1, 1992 An underwater acoustic local area network (ALAN) is being deployed which permits two-way data telemetry between many high-rate, ocean-bottom sensors and a central, surface-deployed receiver in the 10- 40kHz vertical acoustical channel [1]. The oceanbottom ... Full text Cite

Coherent and differentially coherent multiuser detectors for asynchronous CDMA frequency-selective channels

Conference Proceedings IEEE Military Communications Conference MILCOM · January 1, 1992 The authors consider an asynchronous CDMA (code-division multiple-access) frequency-selective Rayleigh fading channel in which a central receiver has knowledge of the signature waveforms of all users. Low-complexity coherent and differentially coherent mul ... Full text Cite

On multiuser detection in asynchronous CDMA flat Rayleigh fading channels

Conference IEEE International Symposium on Personal Indoor and Mobile Radio Communications PIMRC · January 1, 1992 In this paper the performance analysis of lowcomplexity decorrelating detectors will be presented for both coherent and differentially coherent transmission over the multiple-access, frequencynonselective Rayleigh fading channel. While it is known that cor ... Full text Cite

Holographic Photonic Band Gaps

Conference Optics Infobase Conference Papers · January 1, 1991 Cite

A semi-classical analysis of optical code division multiple access

Conference Conference Digest LEOS Summer Topical on Optical Multiple Access Networks · December 1, 1990 The exact error rate has been derived for the noncoherent, optical matched-filter CDMA receiver, which decides for the data of a single user by comparing a photoelectron count to a threshold. The results differ from those of previous work in that they adhe ... Cite

Probability of error of an optical DPSK detector under Brownian laser phase noise

Conference undefined · December 1, 1988 Summary form only given, as follows. The authors analyze an optical, direct-detection DPSK receiver whose error probability is quantum-limited as the transmitting laser linewidth vanishes. The receiver design is based on a binary equiprobable hypothesis te ... Cite

Optimization of a coded aperture coherent scatter spectral imaging system for medical imaging

Conference Proc. SPIE 9412, Medical Imaging 2015: Physics of Medical Imaging, Full text Cite