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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Remote Imaging System Acquisition (RISA) Space Environment Multispectral Imager

Lizarrage, Adrian, Lynn, Brittany, Lange, Jeremiah 10 1900 (has links)
ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, California / The purpose of the NASA Remote Imaging System Acquisition space camera prototype is to integrate multiple optical instruments into a small wireless system using radiation tolerant components. This stage of prototyping was the development of a broadband variable-focus camera that can transmit data wirelessly. A liquid lens in conjunction with a cerium doped double gauss eliminates traditional focusing mechanisms.
2

Remote Imaging System Acquisition (RISA)

Lichtsinn, Wade, McKelvy, Evan, Myrick, Adam, Quihuis, Dominic, Williamson, Jamie 10 1900 (has links)
ITC/USA 2009 Conference Proceedings / The Forty-Fifth Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2009 / Riviera Hotel & Convention Center, Las Vegas, Nevada / NASA's Remote Imaging System Acquisition (RISA) project has the goal of producing a single robust and space-efficient imaging system. This paper will show the progress of the current RISA project iteration, tasked with implementing a Inter-Integrated Circuit (I²C) communications controller on a radiation hardened Field Programmable Gate Array (FPGA), characterizing a liquid lens optical system, and adding a radiation hardened temperature sensor. The optical design focuses on small liquid lenses that can vary focal length with no moving parts. The chosen designs will allow this camera system to meet critical mission objectives and provide reliable service to NASA's astronauts.
3

Remote Imaging System Acquisition Multispectral Imager

Choate, Laura, Lundstrom, Kevin, Pounds, Kevin, Richards, Garrett, Vinal, Eli 10 1900 (has links)
ITC/USA 2011 Conference Proceedings / The Forty-Seventh Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2011 / Bally's Las Vegas, Las Vegas, Nevada / The National Aeronautics and Space Administration's (NASA) Remote Imaging System Acquisition (RISA) camera will integrate the functionalities of existing space cameras. The system operates between 350nm and 1050nm wavelengths, with a MATLAB user interface, uses a CS-mount standard with a CMOS detector, and has a fixed focal plane. The implementation of a liquid lens uses electrical focus adjustments to image from infinity down to one foot. This will allow wireless operation and reduces mechanical failure. All images and video captured will be transmitted wirelessly to a MATLAB program. This data is then processed and stored, allowing for remote imaging.
4

NASA Remote Imaging System Acquisition (RISA) Multispectral Imager Development Updates

Martin, Samuel, Mayer, Jackeline, Owan, Parker, Stephens, Kyle, Suring, Lee 10 1900 (has links)
ITC/USA 2012 Conference Proceedings / The Forty-Eighth Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2012 / Town and Country Resort & Convention Center, San Diego, California / The NASA Remote Imaging System Acquisition (RISA) project is a prototype camera intended to be used by future NASA astronauts. NASA has commissioned the development of this engineering camera to support new mission objectives and perform multiple functions. These objectives require the final prototype to be radiation hardened, multispectral, completely wireless in data transmission and communication, and take high quality still images. This year's team was able to successfully develop an optical system that uses a liquid lens element for focus adjustment. The electrical system uses an Overo Fire computer-on-module (COM) developed by Gumstix. The OMAP processor onboard handles all communication with a monochromatic CMOS sensor, liquid lens control circuitry, pixel data acquisition and processing, and wireless communication with a host computer.
5

Bio-inspired Reconfigurable Elastomer-liquid Lens: Design, Actuation and Optimization

Wei, Kang 13 August 2015 (has links)
No description available.
6

Gabor Domain Optical Coherence Microscopy

Murali, Supraja 01 January 2009 (has links)
Time domain Optical Coherence Tomography (TD-OCT), first reported in 1991, makes use of the low temporal coherence properties of a NIR broadband laser to create depth sectioning of up to 2mm under the surface using optical interferometry and point to point scanning. Prior and ongoing work in OCT in the research community has concentrated on improving axial resolution through the development of broadband sources and speed of image acquisition through new techniques such as Spectral domain OCT (SD-OCT). In SD-OCT, an entire depth scan is acquired at once with a low numerical aperture (NA) objective lens focused at a fixed point within the sample. In this imaging geometry, a longer depth of focus is achieved at the expense of lateral resolution, which is typically limited to 10 to 20 [micro]m. Optical Coherence Microscopy (OCM), introduced in 1994, combined the advantages of high axial resolution obtained in OCT with high lateral resolution obtained by increasing the NA of the microscope placed in the sample arm. However, OCM presented trade-offs caused by the inverse quadratic relationship between the NA and the DOF of the optics used. For applications requiring high lateral resolution, such as cancer diagnostics, several solutions have been proposed including the periodic manual re-focusing of the objective lens in the time domain as well as the spectral domain C-mode configuration in order to overcome the loss in lateral resolution outside the DOF. In this research, we report for the first time, high speed, sub-cellular imaging (lateral resolution of 2 [micro]m) in OCM using a Gabor domain image processing algorithm with a custom designed and fabricated dynamic focus microscope interfaced to a Ti:Sa femtosecond laser centered at 800 nm within an SD-OCM configuration. It is envisioned that this technology will provide a non-invasive replacement for the current practice of multiple biopsies for skin cancer diagnosis. The research reported here presents three important advances to this technology all of which have been demonstrated in full functional hardware conceived and built during the course of this research. First, it has been demonstrated that the coherence gate created by the femtosecond laser can be coupled into a scanning optical microscope using optical design methods to include liquid lens technology that enables scanning below the surface of skin with no moving parts and at high resolution throughout a 2x2x2 mm imaging cube. Second, the integration the variable-focus liquid lens technology within a fixed-optics microscope custom optical design helped increase the working NA by an order of magnitude over the limitation imposed by the liquid lens alone. Thus, this design has enabled homogenous axial and lateral resolution at the micron-level (i.e., 2 [micro]m) while imaging in the spectral domain, and still maintaining in vivo speeds. The latest images in biological specimens clearly demonstrate sub-cellular resolution in all dimensions throughout the imaging volume. Third, this new modality for data collection has been integrated with an automated Gabor domain image registration and fusion algorithm to provide full resolution images across the data cube in real-time. We refer to this overall OCM method as Gabor domain OCM (GD-OCM). These advantages place GD-OCM in a unique position with respect to the diagnosis of cancer, because when fully developed, it promises to enable fast and accurate screening for early symptoms that could lead to prevention. The next step for this technology is to apply it directly, in a clinical environment. This step is underway and is expected to be reported by the next generation of researchers within this group.
7

A Discrete Cylindrical Luneburg Lens With Liquid Layers

Normark Frisk, Curt-Herman, Algarp, Erik January 2020 (has links)
In this project, a cylindrical Luneburg lens isdesigned operating at optical frequencies. A Luneburg lens isa gradient index lens that transforms a point source into aplane wave or vice versa. The lens is rotational symmetric whichallows wide-angle beam scan. In this work, the gradient indexis discretized in layers. The refractive index of each layer isrealized with a transparent liquid. Ray tracing is used to designand evaluate the lens performance. We have simulated Luneburglenses with 4 - 10 layers. Increasing the number of layersimproves the performance. However, difficulties are present inthe manufacturing part of the lens considering that liquids withdesired refractive index cannot be mixed. / I detta projekt designas en cylindrisk Luneburg-lins som fungerar vid optiska frekvenser. En Luneburg-lins är en gradientindexlins som omvandlar en punktkälla till en plan våg eller vice versa. Linsen är rotationssymmetrisk vilket möjliggör vidvinkelstrålescanning. I detta arbete diskretiseras gradienta indexet i lager, brytningsindex för varje lager realiseras med en transparent vätska. Raytracing används för att designa och utvärdera linsprestandan. Vi har simulerat Luneburg-linser med 4 - 10 lager. Genom att öka antalet lager förbättras prestandan. Svårigheter förekommer i linsens tillverkningsprocess med tanke på att vätskor med önskat brytningsindex inte kan blandas. / Kandidatexjobb i elektroteknik 2020, KTH, Stockholm
8

Adaptive Elastomer-liquid Lenses for Advancing the Imaging Capability of Miniaturized Optical Systems

Huang, Hanyang 03 October 2019 (has links)
No description available.

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