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Electrical and Computer Engineering

Air Force Institute of Technology

2012

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Articles 1 - 16 of 16

Full-Text Articles in Engineering

Radar Based Navigation In Unknown Terrain, Kyle J. Kauffman Dec 2012

Radar Based Navigation In Unknown Terrain, Kyle J. Kauffman

Theses and Dissertations

There is a great need to develop non-GPS based methods for positioning and navigation in situations where GPS is not available. This research focuses on the development of an Ultra-Wideband Orthogonal Frequency Division Multiplexed (UWB-OFDM) radar as a navigation sensor in GPS-denied environments. A side-looking vehicle-fixed UWB-OFDM radar is mounted to a ground or aerial vehicle continuously collecting data. A set of signal processing algorithms and methods are developed which use the raw radar data to aide in calculating the vehicle position and velocity via a simultaneous localization and mapping (SLAM) approach. The radar processing algorithms detect strong, persistent, and …


Modeling The Effects Of The Local Environment On A Received Gnss Signal, Marshall E. Haker Dec 2012

Modeling The Effects Of The Local Environment On A Received Gnss Signal, Marshall E. Haker

Theses and Dissertations

There is an ongoing need in the GNSS community for the development of high-fidelity simulators which generate data that replicates what can truly be expected from a challenging environment such as an urban canyon or an indoor environment. The algorithm developed for use in the research in this dissertation, the Signal Decomposition and Parameterization Algorithm (SDPA), is presented in order to respond to this need. This algorithm is designed to decompose a signal received using a GNSS recording and playback system and output parameters that can be used to reconstruct the effects on the signal of the environment local to …


Ground Vehicle Navigation Using Magnetic Field Variation, Jeremiah A. Shockley Sep 2012

Ground Vehicle Navigation Using Magnetic Field Variation, Jeremiah A. Shockley

Theses and Dissertations

The Earth's magnetic field has been the bedrock of navigation for centuries. The latest research highlights the uniqueness of magnetic field measurements based on position due to large scale variations as well as localized perturbations. These observable changes in the Earth's magnetic field as a function of position provide distinct information which can be used for navigation. This dissertation describes ground vehicle navigation exploiting variation in Earth's magnetic field using a self-contained navigation system consisting of only a magnetometer and magnetic field maps. In order to achieve navigation, effective calibration enables repeatable magnetic field measurements from different vehicles and facilitates …


Cross Hallway Detection And Indoor Localization Using Flash Laser Detection And Ranging, Istvan M. Prileszky Jun 2012

Cross Hallway Detection And Indoor Localization Using Flash Laser Detection And Ranging, Istvan M. Prileszky

Theses and Dissertations

A flash LADAR is investigated as a source of navigation information to support cross-hallway detection and relative localization. To accomplish this, a dynamic, flexible simulation was developed that simulated the LADAR and the noise of a LADAR system. Using simulated LADAR data, algorithms were developed that were shown to be effective at detecting cross hallways in simulated ideal environments and in simulated environments with noise. Relative position was determined in the same situations. A SwissRanger SR4000 flash LADAR was then used to collect real data and to verify algorithm performance in real environments. Hallway detection was shown to be possible …


An Application Of Con-Resistant Trust To Improve The Reliability Of Special Protection Systems Within The Smart Grid, Crystal M. Shipman Jun 2012

An Application Of Con-Resistant Trust To Improve The Reliability Of Special Protection Systems Within The Smart Grid, Crystal M. Shipman

Theses and Dissertations

This thesis explores an application of a con-resistant trust mechanism to improve the performance of communications-based special protection systems to further enhance their effectiveness and resiliency. New initiatives in the energy sector are paving the way for the emergent communications-based smart grid technology. Smart grids incorporate modern technologies in an effort to be more reliable and efficient. However, with the benefits of this new technology comes added risk. This research utilizes a con-resistant trust mechanism as a method to quickly identify malicious or malfunctioning protection system nodes in order to mitigate the resulting instabilities in the smart grid. The feasibility …


Multi-Observation Continuous Density Hidden Markov Models For Anomaly Detection In Full Motion Video, Matthew P. Ross Jun 2012

Multi-Observation Continuous Density Hidden Markov Models For Anomaly Detection In Full Motion Video, Matthew P. Ross

Theses and Dissertations

An increase in sensors on the battlefield produces an abundance of collected data that overwhelms the processing capability of the DoD. Automated Visual Surveillance (AVS) seeks to use machines to better exploit increased sensor data, such as by highlighting anomalies. In this thesis, we apply AVS to overhead Full Motion Video (FMV). We seek to automate the classification of soldiers in a simulated combat scenario into their agent types. To this end, we use Multi-Dimensional Continuous Density Hidden Markov Models (MOCDHMMs), a form of HMM which models a training dataset more precisely than simple HMMs. MOCDHMMs are theoretically developed but …


Augmenting The Global Positioning System With Foreign Navigation Systems And Alternative Sensors, Christopher B. Killion Mar 2012

Augmenting The Global Positioning System With Foreign Navigation Systems And Alternative Sensors, Christopher B. Killion

Theses and Dissertations

The United States Global Positioning System (GPS), with its great accuracy, receives extensive use by civilians and military organizations throughout the world. However, in areas with limited or partially obstructed views of the sky, such as amongst tall buildings or imposing geographic features, a position solution can be difficult or impossible to obtain as the limited view of the sky decreases the number of visible satellites. Augmenting the GPS constellation by receiving signals from foreign satellite navigation systems as well as using measurements from inertial and barometric sensors can increase the availability of a position solution in a degraded reception …


Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson Mar 2012

Passive Multistatic Radar Imaging Using An Ofdm Based Signal Of Opportunity, Matthew B. P. Rapson

Theses and Dissertations

This paper demonstrates a proof of concept in using an OFDM-based signal of opportunity for SAR imaging purposes within a passive, multistatic radar construct. Two signal processing methods have been proposed to create phase history data. The same methods are applied in both a simulated software model and an experimental data collection environment to produce simulated SAR images using the CBP imaging algorithm. The images generated from both the experimental and simulated data were observed to be consistent with each other and with expectations in terms of resolution. Coherent addition of the images results in improved image resolution due to …


Covariance Analysis Of Vision Aided Navigation By Bootstrapping, Andrew L. Relyea Mar 2012

Covariance Analysis Of Vision Aided Navigation By Bootstrapping, Andrew L. Relyea

Theses and Dissertations

Inertial Navigation System (INS) aiding using bearing measurements taken over time of stationary ground features is investigated. A cross country flight, in two and three dimensional space, is considered, as well as a vertical drop in three dimensional space. The objective is to quantify the temporal development of the uncertainty in the navigation states of an aircraft INS which is aided by taking bearing measurements of ground objects which have been geolocated using ownship position. It is shown that during wings level flight at constant speed and a fixed altitude, an aircraft that tracks ground objects and over time sequentially …


Distributed Localization Of Active Transmitters In A Wireless Sensor Network, Oba L. Vincent Mar 2012

Distributed Localization Of Active Transmitters In A Wireless Sensor Network, Oba L. Vincent

Theses and Dissertations

In today's military environment, emphasis has been placed on bandwidth efficiency and total use of the available spectrum. Current communication standards divide the spectrum into several different frequency bands, all of which are assigned to one or multiple primary users. Cognitive Radio utilizes potential white spaces that exist between currently defined channels or in time. One under-explored dimension of white space exploration is spatial. If a frequency band is being used in one region, it may be underutilized, or not occupied in another. Using an active localization method can allow for the discovery of spatial white; trying to spatially map …


Low Cost, Low Complexity Sensor Design For Non-Cooperative Geolocation Via Received Signal Strength, Michael S. Butler Mar 2012

Low Cost, Low Complexity Sensor Design For Non-Cooperative Geolocation Via Received Signal Strength, Michael S. Butler

Theses and Dissertations

Obtaining accurate non-cooperative geolocation is vital for persistent surveillance of a hostile emitter. Current research for developing a small, cheap and energy efficient sensor network for non-cooperative geolocation measurements via received signal strength (RSS) is limited. Most existing work focuses on simulating a non-cooperative network (NN) and in doing so, simulated models often ignore localization errors caused from the hardware processing raw RSS data and often model environment-dependent errors as random. By comparing real-time measured non-cooperative geolocation data to a simulated system a more accurate model can be developed. This thesis discusses the development and performance of a small, low …


Air-To-Air Missile Enhanced Scoring With Kalman Smoothing, Jonathon S. Gipson Mar 2012

Air-To-Air Missile Enhanced Scoring With Kalman Smoothing, Jonathon S. Gipson

Theses and Dissertations

A correct estimate of a missile's flight path is essential to USAF test and evaluation efforts. The USAF air-to-air Weapons System Evaluation Program (WSEP) targets unmanned aerial drones in hundreds of live-fire missile tests each year. The current QF-4 drone inventory is expected to be depleted by 2015. The QF-16 Full Scale Aerial Target (FSAT) contract has been awarded to convert usable early model F-16s into remote-controlled drones. The QF-16 will provide a highly-maneuverable, realistic testing environment for 5th generation fighters. To accomplish their mission, WSEP requires a scoring system capable of estimating the trajectory of a missile relative to …


Application Of Game Theory To Improve The Defense Of The Smart Grid, Keith J. Ross Mar 2012

Application Of Game Theory To Improve The Defense Of The Smart Grid, Keith J. Ross

Theses and Dissertations

This thesis presents the development and evaluation of a distributed agent based system using reputation based trust and game theoretic techniques to improve the defense of the future smart grid from cyber-attack and equipment malfunctions. Future smart grid capabilities promise to leverage network technologies to revolutionize the production, transmission, distribution and consumption of electrical power. However, the internet like communication also increase the power grid's vulnerability to cyber-attack. This thesis uses simulation linking power systems with communication networks to demonstrate the benefits of a Distributed Decision Making Communication Enable Special Protection System (SPS) using reputation based trust and game theory …


The Effects Of Cognitive Jamming On Wireless Sensor Networks Used For Geolocation, Michael A. Huffman Mar 2012

The Effects Of Cognitive Jamming On Wireless Sensor Networks Used For Geolocation, Michael A. Huffman

Theses and Dissertations

The increased use of Wireless Sensor Networks (WSN) for geolocation has led to an increased reliance on this technology. Jamming, protecting jamming, and detecting jamming in a WSN are areas of study that have greatly increased in interest. This research uses simulations and data collected from hardware experiments to test the effects of jamming on a WSN. Hardware jamming was tested using a Universal Software Radio Peripheral (USRP) Version 2 to assess the effects of jamming on a cooperative network of Java Sun SPOTs. The research combines simulations and data collected from the hardware experiments to see the effects of …


Uhf Antenna Design For Afit Random Noise Radar, Matthew T. Ludwig Mar 2012

Uhf Antenna Design For Afit Random Noise Radar, Matthew T. Ludwig

Theses and Dissertations

The design of a small ultra-high frequency (UHF) antenna for an ultra-wideband (UWB) random noise radar (RNR) system was undertaken to improve system bandwidth and reduce overall system size. The Vivaldi dipole antenna class showed the greatest potential for high performance in this specific application. After extensive computer simulation, three designs were built using two printed circuit board antenna construction methods. The antipodal chopped Vivaldi dipole antenna, built with a milling machine, achieved a wider bandwidth and more uniform spectral performance characteristics. Though current results show improvement over the current log-periodic antenna (LPA) used on the system, greater performance could …


All Source Sensor Integration Using An Extended Kalman Filter, Timothy R. Penn Mar 2012

All Source Sensor Integration Using An Extended Kalman Filter, Timothy R. Penn

Theses and Dissertations

The global positioning system (GPS) has become an ubiquitous source for navigation in the modern age, especially since the removal of selective availability at the beginning of this century. The utility of the GPS is unmatched, however GPS is not available in all environments. Heavy reliance on GPS for navigation makes the warfighter increasingly vulnerability as modern warfare continues to evolve. This research provides a method for incorporating measurements from a massive variety of sensors to mitigate GPS dependence. The result is the integration of sensor sets that encompass those examined in recent literature as well as some custom navigation …