Physical Sciences and Mathematics Commons^™

Cloud Tracking Winds On Mars Using Emm-Exi Imaging, Shaimaa Ahmed Alblooki

Theses

The Martian atmospheric wind structure is a major unknown in our understanding of Mars’ climate because it is difficult to measure wind remotely. The Emirates eXploration Imager (EXI) instrument on board the Emirates Mars Mission (EMM) takes visible and ultraviolet images of the whole hemisphere of the planet at a time, and can capture complete weather systems at once, along with their evolution over time. This project uses EXI 320 nm observations to measure winds on Mars using Correlation Imaging Velocimetry (CIV), a cloud tracking method based on software developed for laboratory fluid dynamics experiments, and with significant heritage in …

Post-Acquisition Hyperpolarized 29silicon Mr Image Processing For Visualization Of Colorectal Lesions Using A User-Friendly Graphical Interface, Caitlin V Mccowan, Duncan Salmon, Jingzhe Hu, Shivanand Pudakalakatti, Nicholas Whiting, Jennifer S Davis, Daniel D Carson, Niki M Zacharias, Pratip K Bhattacharya, Mary C Farach-Carson

College of Science & Mathematics Departmental Research

Medical imaging devices often use automated processing that creates and displays a self-normalized image. When improperly executed, normalization can misrepresent information or result in an inaccurate analysis. In the case of diagnostic imaging, a false positive in the absence of disease, or a negative finding when disease is present, can produce a detrimental experience for the patient and diminish their health prospects and prognosis. In many clinical settings, a medical technical specialist is trained to operate an imaging device without sufficient background information or understanding of the fundamental theory and processes involved in image creation and signal processing. Here, we …

Enhanced Detection Efficiencies And Reduced False Alarms In Searching For Gravitational Waves From Core Collapse Supernovae, Gaukhar Nurbek

Theses and Dissertations

A supernova is a star that flares up very suddenly and then slowly returns to its former luminosity or, explodes violently with energy $10^{52}$ erg. There are stars which are 10 times or more massive than the Sun, which usually end their lives going supernova. When there is no longer enough fuel for the fusion process in the core of the star and inward gravitational pull of the star’s great mass takes place, the star starts to explode. A series of nuclear reactions starts taking place after the star begins shrinking due to gravity. In the final phase of this …

Optical Study Of 2-D Detonation Wave Stability, Eulaine T. Grodner

Theses and Dissertations

Fundamental optical detonation study of detonations constricted to a 2-d plane propagation, and detonations propagating around a curve. All images were processed using modern image processing techniques. The optical techniques used were shadowgraph, Schlieren, and chemiluminescence. In the 2-Dstraight channels, it was determined wave stability was a factor of cell size. It was also determined the detonation wave thickness (area between the combustion and shockwave) was a factor of how much heat available for the detonation. For the detonations propagating around a curve, it was determined the three main classifications of wave stability were stable, unstable, and detonation wave restart. …

Genetically Encoded Phase Contrast Agents For Digital Holographic Microscopy, Arash Farhadi, Manuel Bedrossian, Justin Lee, Gabrielle H. Ho, Mikhail G. Shapiro, Jay Nadeau

Physics Faculty Publications and Presentations

Quantitative phase imaging and digital holographic microscopy have shown great promise for visualizing the motion, structure and physiology of microorganisms and mammalian cells in three dimensions. However, these imaging techniques currently lack molecular contrast agents analogous to the fluorescent dyes and proteins that have revolutionized fluorescence microscopy. Here we introduce the first genetically encodable phase contrast agents based on gas vesicles. The relatively low index of refraction of the air-filled core of gas vesicles results in optical phase advancement relative to aqueous media, making them a “positive” phase contrast agent easily distinguished from organelles, dyes, or microminerals. We demonstrate this …

A Spatial Localization Of Structural Degradation Areas In The Single Crystal Turbine Blades By Means Of A Neutron Tomography Method, K. M. Nazarov, S. E. Kichanov, E. V. Lukin, A. V. Rutkauskas, B. N. Savenko

Eurasian Journal of Physics and Functional Materials

The single crystal nickel-based superalloy turbine blades have been studied by means of a neutron tomography method as a non-destructive structural probe. Di erences in neutron attenuation coe cients inside volume of metal bodies of the turbine blades have been found. Those observed di erences could be associated with inner structural incoherence areas arising in the process of operation of the turbine blades. Applications of special algorithms for a three-dimensional imaging data analysis allow obtaining a spatial distribution of those areas inside the turbine blades and estimate those volumes. To study a temperature evolution of structural incoherence areas, the additional …

Enhancing Final Image Contrast In Off-Axis Digital Holography Using Residual Fringes, Manuel Bedrossian, Kent Wallace, Eugene Serabyn, Chris Lindensmith, Jay Nadeau

Physics Faculty Publications and Presentations

We show that background fringe-pattern subtraction is a useful technique for removing static noise from off-axis holographic reconstructions and can enhance image contrast in volumetric reconstructions by an order of magnitude in the case for instruments with relatively stable fringes. We demonstrate the fundamental principle of this technique and introduce some practical considerations that must be made when implementing this scheme, such as quantifying fringe stability. This work also shows an experimental verification of the background fringe subtraction scheme using various biological samples.

Erratum: "Imaging The Three‐Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri‐Spot Point Spread Function", Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

In the original paper, a calibration error exists in the image-formation model used to analyze experimental images taken by our microscope, causing a bias in the orientation measurements in Figs. 2 and 3. The updated measurements are shown in Fig. E1. We have also updated the supplementary material for the original article to discuss the revised PSF model and estimation algorithms (supplementary material 2) and show the revised model and measurements (Figs. S1, S3, S7, S8, and S10–S13).

Multiwavelength Digital Holographic Imaging And Phase Unwrapping Of Protozoa Using Custom Fiji Plug-Ins, David Cohoe, Iulia Hanczarek, J. Kent Wallace, Jay Nadeau

Physics Faculty Publications and Presentations

Multiwavelength digital holographic microscopy (DHM) has been used to improve phase reconstructions of digital holograms by reducing 2p phase ambiguities. However, most samples used as test images have been solid or adhered to a surface, making it easy to determine focal planes and correct for chromatic aberration. In this study we apply 3-wavelength off-axis DHM to swimming protozoa containing distinct spectral features such as chlorophyll and carotenoids. We reconstruct the holograms into amplitude and phase images using the angular spectrum method. Methods for noise subtraction, chromatic aberration correction, and image registration are presented for both amplitude and phase. Approaches to …

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis has …

Evaluation And Quantification Of Diffractive Plenoptic Camera Algorithm Performance, Jack A. Shepherd Iii

Theses and Dissertations

A diffractive plenoptic camera is a novel approach to the traditional plenoptic camera which replaces the main optic with a Fresnel zone plate making the camera sensitive to wavelength instead of range. However, algorithms are necessary to reconstruct the image produced by plenoptic cameras. While many algorithms exist for traditional plenoptic cameras, their ability to create spectral images in a diffractive plenoptic camera is unknown. This paper evaluates digital refocusing, super resolution, and 3D deconvolution through a Richardson-Lucy algorithm as well as a new Gaussian smoothing algorithm. All of the algorithms worked well near the Fresnel zone plate design wavelength, …

Improved Space Object Detection Using Short-Exposure Image Data With Daylight Background, David J. Becker, Stephen C. Cain

Faculty Publications

No abstract provided.

Unequal A Priori Probability Multiple Hypothesis Testing In Space Domain Awareness With The Space Surveillance Telescope, Tyler J. Hardy, Stephen C. Cain, Travis F. Blake

Faculty Publications

This paper investigates the ability to improve Space Domain Awareness (SDA) by increasing the number of detectable Resident Space Objects (RSOs) from space surveillance sensors. With matched filter based techniques, the expected impulse response, or Point Spread Function (PSF), is compared against the received data. In the situation where the images are spatially undersampled, the modeled PSF may not match the received data if the RSO does not fall in the center of the pixel. This aliasing can be accounted for with a Multiple Hypothesis Test (MHT). Previously, proposed MHTs have implemented a test with an equal a priori prior …

Heterodyne Ladar System Efficiency Enhancement Using Single-Mode Optical Fiber Mixers, Donald K. Jacob, Martin B. Mark, Bradley D. Duncan

Bradley D. Duncan

A theoretical performance analysis of a heterodyne ladar system incorporating a single-mode fiber receiver has been performed. For our purposes, the performance parameters of interest are the coupling and mixing efficiency of the ladar receiver, as they relate to the overall system carrier-to-noise ratio. For a receiver incorporating a single-mode fiber mixer, the received and local-oscillator fields are matched both spatially and temporally at the detector, yielding 100% mixing efficiency. We have therefore focused our efforts on determining an expression for the efficiency with which a diffuse return from a purely speckle target can be coupled into the receiving leg …

Analysis Of Ladar Range Resolution Enhancement By Sinusoidal Phase Modulation, Leonard Masters, Martin Mark, Bradley Duncan

Bradley D. Duncan

The ability of a ladar system to resolve two or more separate returns from a combined echo is related to the effective correlation bandwidth of the pulse emitted by the ladar system. Phase modulation of an outgoing pulse introduces additional frequency components, which increases the effective correlation bandwidth of the pulse and thus improves the range resolution of the system. In this paper, we discuss the general theoretical basis for achieving improved range resolution using a modulated waveform and a matched filter receiver. We then demonstrate these concepts by considering the particular case of improved range resolution for a sinusoidally …

Fragmentation And Wake Formation In Faint Meteors: Implications For The Structure And Ablation Of Small Meteoroids, Edward Stokan

Electronic Thesis and Dissertation Repository

Meteors with peak magnitudes fainter than +2 are typically called faint meteors, resulting from the atmospheric entry and ablation of meteoroids less massive than 10^-4 kg. The processes of luminous wake formation and fragmentation, which occur during ablation, are poorly understood for faint meteors, and are important constraints for models of meteoroid structure. The goal of this work is to improve understanding of these processes through analysis of high-resolution intensified video observations, and creation of a detailed meteoroid ablation model.

In the first part of this work, thirty faint meteors observed with the Canadian Automated Meteor Observatory (CAMO) are …

Advances In Crystallographic Image Processing For Scanning Probe Microscopy, Peter Moeck, Taylor T. Bilyeu, A. Mainzer Koenig, Jack C. Straton

Physics Faculty Publications and Presentations

Brief overview of advances in image processing for scanning probe microscopes, as related to high resolution images of crystals and arrays of membrane proteins.

Nanometrology Device Standards For Scanning Probe Mmicroscopes And Processes For Their Fabrication And Use, Peter Moeck

Physics Faculty Publications and Presentations

Nanometrology device standards and methods for fabricating and using such devices in conjunction With scanning probe microscopes are described. The fabrication methods comprise: (1) epitaxial growth that produces nanometer sized islands of knoWn morphology, structural, morphological and chemical stability in typical nanometrology environments, and large height-to-width nano-island aspect ratios, and (2) marking suitable crystallographic directions on the device for alignment With a scanning direction.

Joint Transform Correlation With A Synthetic Discrimination Function For Object Classification, Inder K. Purohit

Electrical & Computer Engineering Theses & Dissertations

A novel method using adaptive progressive thresholding (APT) and shifted phase-encoded fringe-adjusted joint transform correlation (SPFJTC) that employs a synthetic discriminant function (SDF) image for object classification is presented in this thesis. An adaptive progressive thresholding scheme first processes the given input scene to separate any objects present in the scene from the background. The preprocessing step results in an image having only the foreground objects, such as boats, trees and other cluttered regions, and hence reduces the search space for the correlation step significantly. The processed irμage is then fed to the shifted phase-encoded fringe-adjusted joint transform correlator, which …

Characterization Of Detonation Phenomena Observed In High-Speed Visible Imagery, Trevor W. Warren

Theses and Dissertations

Measurements for radius, angular velocity, initial time of observation, and final time of observation were made for turbulent vortices around detonation fireballs. A proxy for vortex power, determined through unit analysis, was found to correlate well to initial (and final) time of observation with R² equal to 0.8572. The linear trend on a log₁₀-log₁₀ plot was indicative of a rapid decrease (over 10^-1 s) in power associated with the decay of the fireball. Predictions, based on turbulent spectral theory were made for root-mean-square velocity fluctuations and Reynolds numbers, both as functions of time. In addition, …

Design And Model Verification Of An Infrared Chromotomographic Imaging System, Daniel A. Lemaster

Theses and Dissertations

A prism chromotomographic hyperspectral imaging sensor is being developed to aid in the study of bomb phenomenology. Reliable chromotomographic reconstruction depends on accurate knowledge of the sensor specific point spread function over all wavelengths of interest. The purpose of this research is to generate the required point spread functions using wave optics techniques and a phase screen model of system aberrations. Phase screens are generated using the Richardson-Lucy algorithm for extracting point spread functions and Gerchberg-Saxton algorithm for phase retrieval. These phase screens are verified by comparing the modeled results of a blackbody source with measurements made using a chromotomographic …

Analysis Of Ladar Range Resolution Enhancement By Sinusoidal Phase Modulation, Leonard T. Masters, Martin B. Mark, Bradley D. Duncan

Electro-Optics and Photonics Faculty Publications

The ability of a ladar system to resolve two or more separate returns from a combined echo is related to the effective correlation bandwidth of the pulse emitted by the ladar system. Phase modulation of an outgoing pulse introduces additional frequency components, which increases the effective correlation bandwidth of the pulse and thus improves the range resolution of the system. In this paper, we discuss the general theoretical basis for achieving improved range resolution using a modulated waveform and a matched filter receiver. We then demonstrate these concepts by considering the particular case of improved range resolution for a sinusoidally …

Heterodyne Ladar System Efficiency Enhancement Using Single-Mode Optical Fiber Mixers, Donald K. Jacob, Martin B. Mark, Bradley D. Duncan

Electro-Optics and Photonics Faculty Publications

A theoretical performance analysis of a heterodyne ladar system incorporating a single-mode fiber receiver has been performed. For our purposes, the performance parameters of interest are the coupling and mixing efficiency of the ladar receiver, as they relate to the overall system carrier-to-noise ratio. For a receiver incorporating a single-mode fiber mixer, the received and local-oscillator fields are matched both spatially and temporally at the detector, yielding 100% mixing efficiency. We have therefore focused our efforts on determining an expression for the efficiency with which a diffuse return from a purely speckle target can be coupled into the receiving leg …

Fourier Series And Optical Transform Techniques In Contemporary Optics: An Introduction, Raymond Wilson, Sean Mccreary

Raymond Wilson

Color Image Segmentation, Kimberley A. Mccrae

Theses and Dissertations

The most difficult stage of automated target recognition ATR is segmentation. Current AFIT segmentation problems include faces and tactical targets previous efforts to segment these objects have used intensity and motion cues. This thesis develops a color preprocessing scheme to be used with the other segmentation techniques. A neural network is trained to identify the color of a desired object, eliminating all but that color from the scene. Gabor correlations and 2D wavelet transformations will be performed on stationary images and 3D wavelet transforms on multispectral data will incorporate color and motion detection into the machine visual system. The thesis …

The Effect Of An Adaptive Optical System's Spatio-Temporal Response On Imaging Performance, Patrick M. Harrington

Theses and Dissertations

Ideally, an adaptive optical control system would have instantaneous temporal response and infinite spatial bandwidth. In real systems, the response time of the adaptive optical control system is limited by the integration time of the wave front sensor, the computational time of the control algorithm, and the actuator response time. Additionally, finite inter actuator spacing limits the deformable mirror's ability to reproduce spatial frequencies having a period less than twice this spacing. Although analyses general enough to account for both the temporal and spatial characteristics of the adaptive optical system exist, they are complex and require detailed information regarding the …

Optical Image Segmentation Using Wavelet Correlation, Steven D. Pinski

Theses and Dissertations

This research introduces an optical method of segmenting potential targets using wavelet analysis. Implementation of an optical Harr wavelet is fulfilled using a magneto-optic spatial light modulator (MOSLM). Two methods of controlling wavelet dilation are explored: (1) spatial filtering of a ternary modulated MOSLM; (2) a single aperture positioned in front of a binary modulated MOSLM. Segmentation is performed through Vander Lugt correlation of a binarized image with a binarized optical wavelet. Three different image binarization methods are investigated for use in the correlation scheme: (1) average pixel value over an entire scene; (2) localized 4 x 4 pixel average …