Signal Processing Commons^™

High Fidelity Satellite Navigation Receiver Front-End For Advanced Signal Quality Monitoring And Authentication, Andrew D. Braun

Theses and Dissertations

Over the last several years, interest in utilizing foreign satellite timing and navigation (satnav) signals to augment GPS has grown. Doing so is not without risks; foreign satnav signals must be vetted and determined to be trustworthy before use in military applications. Advanced signal quality monitoring methods can help to ensure that only authentic and reliable satnav signals are utilized. To effectively monitor and authenticate signals, the front-end must impress as little distortions upon the received signal as possible. The purpose of this study is to design, fabricate, and test the performance of a high-fidelity satnav receiver front-end for advanced …

Direct Path Interference Suppression And Received Signal Processing For Ofdm Passive Radar, Aileen Nundu

Theses and Dissertations

Passive bistatic radar (PBR) is a fairly active area of research due to the opportunities offered by the ability to use emitters of opportunity for target detection and tracking as well as Synthetic Aperture Radar (SAR) imaging. There is an increasing variety and availability of signals that can be exploited for passive radar and there is also the advantage of angular diversity offered by the bistatic geometry and the potential for stealth operations afforded a passive receiver. Notwithstanding its merits, PBR is complicated by the inevitable presence of Direct Path Interference (DPI) from the transmitter to the receiver, which can …

Uranium Dioxide Actinide Detection Device Support Design For Space Applications, Jennifer N. Ramos

Theses and Dissertations

Attention concerning the proliferation of nuclear weapons and materials has generated many research initiatives to detect, identify, and locate radiation emitted by actinides. In support of this effort, the `Fission Induced Neutron Detection of Nuclear Materials' (FIND'NM) program was established to comprise a joint effort to explore this issue. The objective also co-extends the Air Force Research Laboratory uranium dioxide (UO2) detection sample growth, characterization, and electrical interface research. AFIT's study accomplishes the design and fabrication of a space-tolerant PCB to support a UO2-based neutron detector. Further design considerations are made with the expectation of the platform to be inside …

Orthogonal Frequency Division Multiplexed Waveform Effects On Passive Bistatic Radar, Forrest D. Taylor

Theses and Dissertations

Communication waveforms act as signals of opportunity for passive radars. However, these signals of opportunity suffer from range-Doppler processing losses due to their high range sidelobes and pulse-diverse waveform aspects. Signals such as the long term evolution (LTE) encode information within the phase and amplitude of the waveform. This research explores aspects of the LTE, such as the encoding scheme and bandwidth modes on passive bistatic Doppler radar. Signal space-time adaptive processing (STAP) performance is evaluated and parameters are compared with the signal to interference-plus-noise ratio (SINR) metric.

Multi-Sensor Data Fusion Between Radio Tomographic Imaging And Noise Radar, Christopher Vergara

Theses and Dissertations

The lack of situational awareness within an operational environment is a problem that carries high risk and expensive consequences. Radio Tomographic Imaging (RTI) and noise radar are two proven technologies capable of through-wall imaging and foliage penetration. The intent of this thesis is to provide a proof of concept for the fusion of data from RTI and noise radar. The output of this thesis will consist of a performance comparison between the two technologies followed by the derivation of a fusion technique to produce a single image. Proposals have been made for the integration of multiple-input multiple-output (MIMO) radar with …

Interactive Simulations In Signals And Systems, Anthony Richardson

ASEE IL-IN Section Conference

Several interactive simulations that promote a better understanding of concepts traditionally encountered in an undergraduate Signals and Systems course are described. The simulations were developed to support the text “Signals & Systems: Theory and Applications” by Ulaby and Yagle. The text and all simulation programs are available for free download (ss2.eecs.umich.edu) as part of the Free Electrical Engineering Textbook Initiative from the University of Michigan.

All simulations use graphical control elements that allow the student to interact with the simulation. Many of the simulations use either real audio or image data so that the student can vary parameters of the …

Design Of A Low-Cost Data Acquisition System For Rotordynamic Data Collection, Gregory S. Pellegrino

Master's Theses

A data acquisition system (DAQ) was designed based on the use of a STM32 microcontroller. Its purpose is to provide a transparent and low-cost alternative to commercially available DAQs, providing educators a means to teach students about the process through which data are collected as well as the uses of collected data. The DAQ was designed to collect data from rotating machinery spinning at a speed up to 10,000 RPM and send this data to a computer through a USB 2.0 full-speed connection. Multitasking code was written for the DAQ to allow for data to be simultaneously collected and transferred …

Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler

Master's Theses

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems …

A Focal Plane Array And Electronics Model For Cmos And Ccd Sensors In The Afit Sensor And Scene Emulation Tool (Asset), Fernando D. Fernandez

Theses and Dissertations

Electro-optical and infrared (EO/IR) sensor models are useful tools that can facilitate understanding a system's behavior without expensive and time-consuming testing of an actual system. EO/IR models are especially important to the military industry where truth data is required but is sometimes impractical to obtain through experimentation due to expense or difficulties in procuring hardware. This work describes implementation of a focal plane array (FPA) model of charge-coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) photodetectors as a component in the Air Force Institute of Technology (AFIT) Sensor and Scene Emulation Tool (ASSET). The FPA model covers conversion of photo-generated …

Deep-Turbulence Wavefront Sensing Using Digital Holography In The On-Axis Phase Shifting Recording Geometry With Comparisons To The Self-Referencing Interferometer, Douglas E. Thornton, Mark F. Spencer, Glen P. Perram

Faculty Publications

In this paper, we study the use of digital holography in the on-axis phase-shifting recording geometry for the purposes of deep-turbulence wavefront sensing. In particular, we develop closed-form expressions for the field-estimated Strehl ratio and signal-to-noise ratio for three separate phase-shifting strategies—the four-, three-, and two-step methods. These closed-form expressions compare favorably with our detailed wave-optics simulations, which propagate a point-source beacon through deep-turbulence conditions, model digital holography with noise, and calculate the Monte Carlo averages associated with increasing turbulence strengths and decreasing focal-plane array sampling. Overall, the results show the four-step method is the most efficient phase-shifting strategy and …

Improving Regional And Teleseismic Detection For Single-Trace Waveforms Using A Deep Temporal Convolutional Neural Network Trained With An Array-Beam Catalog, Joshua T. Dickey, Brett J. Borghetti, William Junek

Faculty Publications

The detection of seismic events at regional and teleseismic distances is critical to Nuclear Treaty Monitoring. Traditionally, detecting regional and teleseismic events has required the use of an expensive multi-instrument seismic array; however in this work, we present DeepPick, a novel seismic detection algorithm capable of array-like detection performance from a single-trace. We achieve this performance through three novel steps: First, a high-fidelity dataset is constructed by pairing array-beam catalog arrival-times with single-trace waveforms from the reference instrument of the array. Second, an idealized characteristic function is created, with exponential peaks aligned to the cataloged arrival times. Third, a deep …

Fall Detection Using Channel State Information From Wifi Devices, D.M Sameera Palipana

PhDs

Falls among the independently living elderly population are a major public health worry, leading to injuries, loss of confidence to live independently and even to death. Each year, one in three people aged 65 and older falls and one in five of them suffers fatal or non fatal injuries. Therefore, detecting a fall early and alerting caregivers can potentially save lives and increase the standard of living. Existing solutions, e.g. push-button, wearables, cameras, radar, pressure and vibration sensors, have limited public adoption either due to the requirement for wearing the device at all times or installing specialized and expensive infrastructure. …

Online Learning Of The Spatial-Temporal Channel Variation In Underwater Acoustic Communication Networks, Wensheng Sun

Dissertations, Master's Theses and Master's Reports

Influenced by environmental conditions, underwater acoustic (UWA) communication channels exhibit spatial and temporal variations, posing significant challenges for UWA networking and applications. This dissertation develops statistical signal processing approaches to model and predict variations of the channel and relevant environmental factors. Firstly, extensive field experiments are conducted in the Great Lakes region. Three types of the freshwater river/lake acoustic channels are characterized in the aspects of statistical channel variations and sound propagation loss, including stationary, mobile and under-ice acoustic channels. Statistical data analysis shows that relative to oceanic channels, freshwater river/lake channels have larger temporal coherence, higher correlation among densely …

Sniffing, Decoding And Decryption Of Gsm Signals Using Low Cost Hardware And Open-Source Software, Muhammad Talha Choudhry

Dissertations and Theses

We have participated in the creation of almost two terabytes of tables aimed at cracking A5/1, the most common ciphering algorithm used in GSM. Given 114-bit of known plaintext, we are able to recover the session key with a hit rate of 19%. The tables are expected to be unique as they provide the best coverage yet known to the authors and research workers and they are the first step in a real-world passive attack against GSM. An initial investigation and analysis into the air interface of GSM were performed, from both a theoretical and practical point of view. These …

Sensor Placement For Damage Localization In Sensor Networks, Fereshteh Firouzi

Theses and Dissertations

The objective of this thesis is to formulate and solve the sensor placement problem for damage localization in a sensor network. A Bayesian estimation problem is formulated with the time-of-flight (ToF) measurements. In this model, ToF of lamb waves, which are generated and received by piezoelectric sensors, is the total time for each wave to be transmitted, reflected by the target, and received by the sensor. The ToF of the scattered lamb wave has characteristic information about the target location. By using the measurement model and prior information, the target location is estimated in a centralized sensor network with a …

Effect Of Sensor Errors On Autonomous Steering Control And Application Of Sensor Fusion For Robust Navigation, Shuvodeep Bhattacharjya

Dissertations, Master's Theses and Master's Reports

Autonomous steering control is one the most important features in autonomous vehicle navigation. The nature and tuning of the controller decides how well the vehicle follows a defined trajectory. A poorly tuned controller can cause the vehicle to oversteer or understeer at turns leading to deviation from a defined path. However, controller performance also depends on the state–feedback system. If the states used for controller input are noisy or has bias / systematic error, the navigation performance of the vehicle is affected irrespective of the control law and controller tuning. In this report, autonomous steering controller analysis is done for …

Estimation And Prediction Of The Human Gait Dynamics For The Control Of An Ankle-Foot Prosthesis, Guilherme Aramizo Ribeiro

Dissertations, Master's Theses and Master's Reports

With the growing population of amputees, powered prostheses can be a solution to improve the quality of life for many people. Powered ankle-foot prostheses can be made to behave similar to the lost limb via controllers that emulate the mechanical impedance of the human ankle. Therefore, the understanding of human ankle dynamics is of major significance. First, this work reports the modulation of the mechanical impedance via two mechanisms: the co-contraction of the calf muscles and a change of mean ankle torque and angle. Then, the mechanical impedance of the ankle was determined, for the first time, as a multivariable …

Mesh Node Communication System For Fire Figthers, Eric E. Hamke, Trace Norris, Jessica E. Ladd, Jeffrey K. Eaton, Jicard J. Malveaux, Manish Bhattarai, Ramiro Jordan, Manel Martinez-Ramon

Electrical & Computer Engineering Technical Reports

This report describes the prototype and demonstration of a reliable local area network (LAN) of devices able to interconnect a crew of fire fighters with a communications node. The data consists of images for thermal cameras at a given rate and other low bandwith data taken from the different sensors of the fire fighter gear, that are connected to the transmitter using a Bluetooth personal area network (PAN). The physical environment is indoors and it is expected that all nodes of the communication networks are distributed in different positions into a building.

Dynamic Voltage Rail Audio Amplifier, Evan Von Duhn, Timothy Oshatiouk, Slavisa Tosanovic, Andrew Cantrell

Williams Honors College, Honors Research Projects

The goal of this project is to create a high-quality, power-efficient audio amplifier. Most modern audio amplifiers use a constant amount of power regardless of the signal that is being amplified. This means that both loud and quiet portions of the audio signal require the same amount of power to amplify. The idea for this high-quality, power-efficient audio amplifier is that the quieter portions of the audio signal can be amplified using less power. This will be achieved by first analyzing the audio signal and controlling the power source based on the signal’s needs. Therefore, louder parts of the audio …