Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- FPGA (5)
- Radio astronomy (3)
- Xilinx (3)
- ARROW (2)
- ASCAT (2)
-
- Aeronautical telemetry (2)
- BYU (2)
- Digital signal processing (2)
- None (2)
- OSCAT (2)
- PECVD (2)
- Phased array feed (2)
- Phased array feeds (2)
- Radio frequency interference (2)
- Reliability (2)
- Remote sensing (2)
- Scrubbing (2)
- Sea ice (2)
- Water absorption (2)
- ARM processor (1)
- Aaron Hawkins (1)
- Acoustics (1)
- Aerospace (1)
- Algorithms (1)
- Architecture (1)
- Array systems (1)
- Automatic Target Detection (1)
- Battery (1)
- Beamforming (1)
- Biosensor (1)
Articles 1 - 26 of 26
Full-Text Articles in Engineering
Multiple Target Tracking In Realistic Environments Using Recursive-Ransac In A Data Fusion Framework, Jeffrey Dyke Millard
Multiple Target Tracking In Realistic Environments Using Recursive-Ransac In A Data Fusion Framework, Jeffrey Dyke Millard
Theses and Dissertations
Reliable track continuity is an important characteristic of multiple target tracking (MTT) algorithms. In the specific case of visually tracking multiple ground targets from an aerial platform, challenges arise due to realistic operating environments such as video compression artifacts, unmodeled camera vibration, and general imperfections in the target detection algorithm. Some popular visual detection techniques include Kanade-Lucas-Tomasi (KLT)-based motion detection, difference imaging, and object feature matching. Each of these algorithmic detectors has fundamental limitations in regard to providing consistent measurements. In this thesis we present a scalable detection framework that simultaneously leverages multiple measurement sources. We present the recursive random …
Phased-Array Feed Instrumentation And Processing For Astronomical Detection, Interference Mitigation, And Transient Parameter Estimation, Richard Allen Black
Phased-Array Feed Instrumentation And Processing For Astronomical Detection, Interference Mitigation, And Transient Parameter Estimation, Richard Allen Black
Theses and Dissertations
Radio astronomy, the survey and study of naturally occurring astronomical radio signals, is a challenging field in terms of engineering requirements. The typical astronomical signal of interest is incredibly faint, resulting in very low signal-to-noise ratios (SNRs) on the order of -30 dB or lower. To detect such signals, one must have an uncommonly low and stable receiver noise temperature, high gain through large aperture reflectors, and state-of-the-art signal processing algorithms. One must also be able to mitigate the effects of interference, the presence of which, even if extremely weak, can completely mask the faint astronomical signals of interest. To …
Relative Navigation Of Micro Air Vehicles In Gps-Degraded Environments, David Orton Wheeler
Relative Navigation Of Micro Air Vehicles In Gps-Degraded Environments, David Orton Wheeler
Theses and Dissertations
Most micro air vehicles rely heavily on reliable GPS measurements for proper estimation and control, and therefore struggle in GPS-degraded environments. When GPS is not available, the global position and heading of the vehicle is unobservable. This dissertation establishes the theoretical and practical advantages of a relative navigation framework for MAV navigation in GPS-degraded environments. This dissertation explores how the consistency, accuracy, and stability of current navigation approaches degrade during prolonged GPS dropout and in the presence of heading uncertainty. Relative navigation (RN) is presented as an alternative approach that maintains observability by working with respect to a local coordinate …
Advancements In Radio Astronomical Array Processing: Digital Back End Development And Interferometric Array Interference Mitigation, Mitchell Costus Burnett
Advancements In Radio Astronomical Array Processing: Digital Back End Development And Interferometric Array Interference Mitigation, Mitchell Costus Burnett
Theses and Dissertations
The Brigham Young University (BYU) Radio Astronomy Systems group, in collaboration with the National Radio Astronomy Observatory (NRAO), the Center for Astrophysics at West Virginia University (WVU), and the Green Bank Observatory (GBO) have developed, and commissioned, a broadband real-time digital back end processing system for a 38-element phased array feed (PAF) with 150 MHz of instantaneous bandwidth. This system is capable of producing coarse and fine channel correlations, and implements a real-time beamformer that forms 7 simultaneous dual-polarized beams. This thesis outlines the hardware and software development for the digital back end and presents on-telescope commissioning results. This system …
Characterization Of Mechanical Properties Of Battery Electrode Films From Acoustic Resonance Measurements, Kathryn Lanae Dallon
Characterization Of Mechanical Properties Of Battery Electrode Films From Acoustic Resonance Measurements, Kathryn Lanae Dallon
Theses and Dissertations
Measurements of the mechanical properties of lithium-ion battery electrode films can be used to quantify and improve manufacturing processes and to predict the mechanical and electrochemical performance of the battery. This thesis demonstrates the use of acoustic resonances to distinguish among commercial-grade battery films with different active electrode materials, thicknesses, and densities. Resonances are excited in a clamped circular area of the film using a pulsed infrared laser or speaker and responses are measured using an electret condenser microphone. A numerical model is used to quantify the sensitivity of resonances to changes in mechanical properties. When the numerical model is …
Real-Time Beamforming Algorithms For The Focal L-Band Array On The Green Bank Telescope, Mark William Ruzindana
Real-Time Beamforming Algorithms For The Focal L-Band Array On The Green Bank Telescope, Mark William Ruzindana
Theses and Dissertations
A phased array feed (PAF) provides a contiguous, electronically synthesized wide field of view for large-dish astronomical observatories. Significant progress has been made in recent years in improving the sensitivity of PAF receivers though optimizing the design of the antenna array, cryogenic cooling of the front end, and implementation of real-time correlation and beamforming in digital signal processing. FLAG is a 19 dual-polarized element phased array with cryogenic LNAs, direct digitization of RF signals at the front end, digital signal transport over fiber, and a real time signal processing back end with up to 150 MHz bandwidth. The digital back …
Design And Evaluation Of A Cmos Contact-Imaging System For Microfluidics, Andres Moroni Galan Cherrez
Design And Evaluation Of A Cmos Contact-Imaging System For Microfluidics, Andres Moroni Galan Cherrez
Theses and Dissertations
A CMOS contact-imaging system for microfluidics is presented. The microsystem integrates a five-layer PDMS microfluidic network and a CMOS image sensor fabricated in a standard 0.18 µm technology. The CMOS image sensor consists of two 10×1-pixel array, an amplifier, and a control logic. The imager is able to achieve a low dark signal of 1.67 mV/s, a maximum integration time of 514 s, and a high dynamic range of 75.2 dB at 1 s integration time. The microfluidic device integrates several actuated valve to achieve a fully automated lab-on-a-chip. This work also presents a quantitative comparison of the photomultiplier tube …
Design And Evaluation Of A Cmos Contact-Imaging System For Microfluidics, Andres Moroni Galan Cherrez
Design And Evaluation Of A Cmos Contact-Imaging System For Microfluidics, Andres Moroni Galan Cherrez
Theses and Dissertations
A CMOS contact-imaging system for microfluidics is presented. The microsystem integrates a five-layer PDMS microfluidic network and a CMOS image sensor fabricated in a standard 0.18 ïm technology. The CMOS image sensor consists of two 10×1-pixel array, an amplifier, and a control logic. The imager is able to achieve a low dark signal of 1.67 mV/s, a maximum integration time of 514 s, and a high dynamic range of 75.2 dB at 1 s integration time. The microfluidic device integrates several actuated valve to achieve a fully automated lab-on-a-chip. This work also presents a quantitative comparison of the photomultiplier tube …
Improved Single Molecule Detection Platform Using A Buried Arrow Design, Thomas Allen Wall
Improved Single Molecule Detection Platform Using A Buried Arrow Design, Thomas Allen Wall
Theses and Dissertations
As the microelectronics industry pushes microfabrication processes further, the lab-on-a-chip field has continued to piggy-back off the industry's fabrication capabilities with the goal of producing total chemical and biological systems on small chip-size platforms. One important function of such systems is the ability to perform single molecule detection. There are currently many methods being researched for performing single molecule detection, both macro and micro in scale. This dissertation focuses on an optofluidic, lab-on-a-chip platform called the ARROW biosensor, which possesses several advantages over macro-scale single molecule detection platforms. These advantages include an amplification-free detection scheme, cheap parallel fabrication techniques, rapid …
Vivado Design Interface: Enabling Cad-Tool Design For Next Generation Xilinx Fpga Devices, Thomas James Townsend
Vivado Design Interface: Enabling Cad-Tool Design For Next Generation Xilinx Fpga Devices, Thomas James Townsend
Theses and Dissertations
The popularity of field-programmable gate arrays (FPGA) has grown in recent years due to their potential performance advantages over sequential software, and as a prototyping platform for application-specific integrated circuits (ASIC). Vendors such as Xilinx offer automated tool suites that can be used to program FPGAs based on a RTL description. These tool suites are sufficient forgeneral users, but they usually don't provide the opportunity to integrate custom computer-aideddesign (CAD) tools into the regular design flow. Xilinx first offered this capability in their ISE tool suite with the Xilinx Design Language (XDL). Using XDL, a Xilinx design could be extracted …
High-Voltage Measurements Using Slab-Coupled Optical Sensors, Legrand Jared Shumway
High-Voltage Measurements Using Slab-Coupled Optical Sensors, Legrand Jared Shumway
Theses and Dissertations
This work highlights slab coupled optical sensors (SCOS) and their ability to measure high voltages. Although other high voltage measurement techniques exist, most of these techniques are electrical devices and are therefore more susceptible to stray ground currents and other electromagnetic interferences (EMI), which may cause signal distortion. Optical sensors are less susceptible to such interferences and these sensors, such as the Pockels cell, have been used in measuring high voltage. SCOS offer an alternative method of measuring high voltage optically. Consisting of an optical fiber and an electro-optic slab waveguide, SCOS have the advantage of being very small in …
Academic Packing For Commercial Fpga Architectures, Travis D. Haroldsen
Academic Packing For Commercial Fpga Architectures, Travis D. Haroldsen
Theses and Dissertations
With a few exceptions, academic packing algorithms for FPGAs are typically applied solely to theoretical architectures. This has allowed the algorithms to focus on the basic components of packing while abstracting away many of the details dictated by real hardware. As commercially available FPGAs have advanced, however, the academic algorithms and architectures have diverged significantly from their commercial counterparts. In this dissertation, the RapidSmith 2 framework is presented. This framework accurately reflects the architecture of Xilinx FPGAs and provides support for integrating custom tools into the commercial CAD tools. Using this framework, the RSVPack packing algorithm is implemented. The RSVPack …
Improved Leaky-Mode Waveguide Spatial Light Modulators For Three Dimensional Displays, Scott Alexander Gneiting
Improved Leaky-Mode Waveguide Spatial Light Modulators For Three Dimensional Displays, Scott Alexander Gneiting
Theses and Dissertations
This thesis improves on the design of the leaky-mode spatial light modulator, LMW-SLM, presented by Dr. Smalley[1]. Improvements include: input coupling gratings, a pulsed laser input, output coupling gratings, and a 3D printed adjustable module for the stabilization of critical alignments. First, input coupling gratings reduce the cost of the LMW-SLM from $500 to around $2, a drop in cost of over two orders of magnitude. This enables multiple modulators to be used in a single display and allows for an inexpensive modular design to be created. Second, a pulsed laser input allows for image creation without the use of …
A Graphical Representation Of Exposed Parallelism, Gustavo Enrique Rodriguez Villamizar
A Graphical Representation Of Exposed Parallelism, Gustavo Enrique Rodriguez Villamizar
Theses and Dissertations
Modern-day microprocessors are measured in part by their parallel performance. Parallelizing sequential programs is a complex task, requiring data dependence analysis of the program constructs. Researchers in the field of parallel optimization are working on shifting the optimization effort from the programmer to the compiler. The goal of this work is for the compiler to visually expose the parallel characteristics of the program to researchers as well as programmers for a better understanding of the parallel properties of their programs. In order to do that we developed Exposed Parallelism Visualization (EPV), a statically-generated graphical tool that builds a parallel task …
Flexible Micro-N-Line Probe And Apparatus To Characterize Electronic Conductivity Of Li-Ion Battery Electrode Films, Derek Van Clement
Flexible Micro-N-Line Probe And Apparatus To Characterize Electronic Conductivity Of Li-Ion Battery Electrode Films, Derek Van Clement
Theses and Dissertations
A key metric that affects Li-ion battery cell performance is the electronic conductivity of the electrode films. Previous research has found that the conductivity of electrodes is not homogeneous throughout the entirety of the deposited film area. To further characterize the non-homogeneity of the conductivity of electrode films, a micro-N-line probe and a micro-flex-line probe were developed to take micro-scale conductivity measurements of thin-film battery electrodes in a non-destructive manner. These devices have been validated by comparing test results to those of it's predecessor, the micro-four-line probe, on various commercial-quality Li-ion battery electrodes. Results show that there is significant variation …
Estimation Of Size And Rotations Of Icebergs From Historical Data Utilizing Scatterometer Data, Jeffrey Scott Budge
Estimation Of Size And Rotations Of Icebergs From Historical Data Utilizing Scatterometer Data, Jeffrey Scott Budge
Theses and Dissertations
In this thesis, the development and methodology of a new, consolidated BYU/NIC Antarctic Iceberg Tracking Database is presented. The new database combines data from the original BYU daily iceberg tracking database derived from scatterometers, and the National Ice Center's weekly Antarctic iceberg tracking database derived from mostly optical and infrared sensors. Using this data, interpolation methods and statistical analyses of iceberg locations are discussed. The intent of this database is to consolidate iceberg location data in order to increase accessibility to users.Active microwave remote sensing instruments are used to track tabular icebergs and provide a daily estimate of their positions …
A Survey Of Sparse Channel Estimation In Aeronautical Telemetry, Christopher James Hogstrom
A Survey Of Sparse Channel Estimation In Aeronautical Telemetry, Christopher James Hogstrom
Theses and Dissertations
Aeronautical telemetry suffers from multipath interference, which can be resolved through the use of equalizers at the receiver. The coefficients of data-aided equalizers are computed from a channel estimate. Most channels seen in aeronautical telemetry are sparse, meaning that most of the coefficients of the channel are zero or nearly zero. The maximum likelihood (ML) estimate does not always produce a sparse channel estimate. This thesis surveys a number of sparse estimation algorithms that produce a sparse channel estimate and compares the post-equalizer bit error rates (BER) using these sparse estimates with the post-equalizer BER using the ML estimate. I …
Multipath Channel Considerations In Aeronautical Telemetry, Edem Coffie Gagakuma
Multipath Channel Considerations In Aeronautical Telemetry, Edem Coffie Gagakuma
Theses and Dissertations
This thesis describes the use of scattering functions to characterize time-varying multipath radio channels. Channel Impulse responses were measured at Edwards Air Force Base (EAFB) and scattering functions generated from the impulse response data. From the scattering functions we compute the corresponding Doppler power spectrum and multipath intensity profile. These functions completely characterize the signal delay and the time varying nature of the channel in question and are used by systems engineers to design reliable communications links. We observe from our results that flight paths with ample reflectors exhibit significant multipath events. We also examine the bit error rate (BER) …
Gpu Implementation Of Data-Aided Equalizers, Jeffrey Thomas Ravert
Gpu Implementation Of Data-Aided Equalizers, Jeffrey Thomas Ravert
Theses and Dissertations
Multipath is one of the dominant causes for link loss in aeronautical telemetry. Equalizers have been studied to combat multipath interference in aeronautical telemetry. Blind equalizers are currently being used with SOQPSK-TG. The Preamble Assisted Equalization (PAQ) project studied data-aided equalizers with SOQPSK-TG. PAQ compares, side-by-side, no equalization, blind equalization, and five data-aided equalization algorithms: ZF, MMSE, MMSE-initialized CMA, and frequency domain equalization. This thesis describes the GPU implementation of data-aided equalizer algorithms. Static lab tests, performed with channel and noise emulators, showed that the MMSE, ZF, and FDE1 show the best and most consistent performance.
Using On-Chip Error Detection To Estimate Fpga Design Sensitivity To Configuration Upsets, Andrew Mark Keller
Using On-Chip Error Detection To Estimate Fpga Design Sensitivity To Configuration Upsets, Andrew Mark Keller
Theses and Dissertations
SRAM-based FPGAs provide valuable computation resources and reconfigurability; however, ionizing radiation can cause designs operating on these devices to fail. The sensitivity of an FPGA design to configuration upsets, or its SEU sensitivity, is an indication of a design's failure rate. SEU mitigation techniques can reduce the SEU sensitivity of FPGA designs in harsh radiation environments. The reliability benefits of these techniques must be determined before they can be used in mission-critical applications and can be determined by comparing the SEU sensitivity of an FPGA design with and without these techniques applied to it. Many approaches can be taken to …
High-Speed Programmable Fpga Configuration Memory Access Using Jtag, Ammon Bradley Gruwell
High-Speed Programmable Fpga Configuration Memory Access Using Jtag, Ammon Bradley Gruwell
Theses and Dissertations
Over the past couple of decades Field Programmable Gate Arrays (FPGAs) have become increasingly useful in a variety of domains. This is due to their low cost and flexibility compared to custom ASICs. This increasing interest in FPGAs has driven the need for tools that both qualify and improve the reliability of FPGAs for applications where the reconfigurability of FPGAs makes them vulnerable to radiation upsets such as in aerospace environments. Such tools ideally work with a wide variety of devices, are highly programmable but simple to use, and perform tasks at relatively high speeds. Of the various FPGA configuration …
Improvements, Algorithms And A Simulation Model For A Compact Phased-Array Radar For Uas Sense And Avoid, Adam Kaleo Roberts
Improvements, Algorithms And A Simulation Model For A Compact Phased-Array Radar For Uas Sense And Avoid, Adam Kaleo Roberts
Theses and Dissertations
Unmanned aerial systems (UAS) are an influential technology which can enhance life in multiple ways. However, they must be able to sense and operate safely with manned aircraft. Radar is an attractive sensor for UAS because of its all-weather performance. It is challenging, though, to meet the size, weight, and power (SWaP) limitations of UAS and especially small-UAS while still maintaining the needed sensing capability. A working FMCW radar prototype has been created which meets the SWaP requirement of small-UAS. A simulation model for the radar was developed to test the processing algorithms of the radar and proved to be …
High-Sensitivity Phased Arrays For Radio Astronomy And Satellite Communications, Junming Diao
High-Sensitivity Phased Arrays For Radio Astronomy And Satellite Communications, Junming Diao
Theses and Dissertations
Radio astronomy is used to study stars, galaxies, black holes and gas clouds radiation at radio frequencies. Detecting extremely weak signals from deep space radio sources requires high sensitive feed system associated with large dish antennas. The key figure of merit is survey speed, or the time required to map a region of the sky to a given source flux density. Survey speed is proportional to the frequency bandwidth, the field of view or observable region of the sky, and the squared sensitivity, where sensitivity is related to reflector aperture efficiency and system noise temperature. Compared to the traditional single …
Extension Of The Quikscat Sea Ice Extent Data Set With Oscat And Ascat Data, Jordan Curtis Hill
Extension Of The Quikscat Sea Ice Extent Data Set With Oscat And Ascat Data, Jordan Curtis Hill
Theses and Dissertations
Polar sea ice measurements are an important contribution to global climate models. Passive and active microwave remote sensing instruments are used to track global trends in polar sea ice growth and retreat from day to day. A scatterometer sea ice extent data set is valuable for comparison with other radiometer data sets and ground based measurements. This scatterometer sea ice record began with the NASA Scatterometer (NSCAT) and continued with the Quick Scatterometer (QuikSCAT) data set. The Ku-band Oceansat-2 scatterometer (OSCAT) is very similar to the Quick Scatterometer, which operated from 1999 to 2009. OSCAT continues the Ku-band scatterometer data …
Preserving Optical Confinement In Pecvd Sio2 Waveguides By Control Of Thin-Film Stress, Steven Jay Hammon
Preserving Optical Confinement In Pecvd Sio2 Waveguides By Control Of Thin-Film Stress, Steven Jay Hammon
Theses and Dissertations
Researchers at Brigham Young University (BYU) have developed an optical biosensor that can quickly analyze a sample to detect any type of nucleic acid based organism, such as viruses or bacteria. The biosensor's reliability over time is compromised due to water absorbing into the SiO2 waveguides of the chip. It was hypothesized that keeping the thin-film stress of the waveguides close to zero would slow or stop water absorption from occurring. Completion of this thin-film study relied upon a new plasma enhanced chemical vapor deposition (PECVD) machine and a new 3-D optical profilometer, both of which were installed in …
A Reconfigurable Trusted Platform Module, Matthew David James
A Reconfigurable Trusted Platform Module, Matthew David James
Theses and Dissertations
A Trusted Platform Module (TPM) is a security device included in most modern desktop and laptop computers. It helps keep the computing environment secure by isolating cryptographic functions and data from the CPU. A TPM is usually implemented with a small microcontroller which is near the main processor. In addition to a microcontroller, it may employ hardware acceleration to assist in cryptographic computations. When vulnerabilities are found, or new algorithms developed, TPMs become obsolete because the hardware accelerators cannot be upgraded. This thesis presents a proof of concept implementation of a TPM on an FPGA. By using an FPGA, the …