Mismatched Filter Effects On Synthetic Aperture Radar Image Quality Metrics,
2020
Air Force Institute of Technology
Mismatched Filter Effects On Synthetic Aperture Radar Image Quality Metrics, Jerrod M. Kempf
Theses and Dissertations
Detection of targets across a wide dynamic range is an enduring challenge in radar. This work formulates a modified least-squares mismatched filter that greatly reduces these sidelobes in order to enable the detection of small radar cross section targets in the presence of considerably larger scatterers, increasing the dynamic range. Unlike previous mismatched filters, the proposed filter is applicable to noisy, oversampled signals with no requirements on signal structure. Range profiles and images are presented to demonstrate the superior sidelobe suppression of the modified least-squares mismatched filter in comparison to the commonly employed matched filter. Various weighting vectors are introduced …
Object Detection With Deep Learning To Accelerate Pose Estimation For Automated Aerial Refueling,
2020
Air Force Institute of Technology
Object Detection With Deep Learning To Accelerate Pose Estimation For Automated Aerial Refueling, Andrew T. Lee
Theses and Dissertations
Remotely piloted aircraft (RPAs) cannot currently refuel during flight because the latency between the pilot and the aircraft is too great to safely perform aerial refueling maneuvers. However, an AAR system removes this limitation by allowing the tanker to directly control the RP A. The tanker quickly finding the relative position and orientation (pose) of the approaching aircraft is the first step to create an AAR system. Previous work at AFIT demonstrates that stereo camera systems provide robust pose estimation capability. This thesis first extends that work by examining the effects of the cameras' resolution on the quality of pose …
Extracting Range Data From Images Using Focus Error,
2020
Air Force Institute of Technology
Extracting Range Data From Images Using Focus Error, Erik M. Madden
Theses and Dissertations
Air-to-air refueling (AAR) has become a staple when performing long missions with aircraft. With modern technology, however, people have begun to research how to perform this task autonomously. Automated air-to-air refueling (A3R) is this exact concept. Combining many different systems, the idea is to allow computers on the aircraft to link up via the refueling boom, refuel, and detach before resuming pilot control. This document lays out one of the systems that is needed to perform A3R, namely, the system that extracts range data. While stereo cameras perform such tasks, there is interest in finding other ways of accomplishing the …
A Comparative Evaluation Of The Detection And Tracking Capability Between Novel Event-Based And Conventional Frame-Based Sensors,
2020
Air Force Institute of Technology
A Comparative Evaluation Of The Detection And Tracking Capability Between Novel Event-Based And Conventional Frame-Based Sensors, James P. Boettiger
Theses and Dissertations
Traditional frame-based technology continues to suffer from motion blur, low dynamic range, speed limitations and high data storage requirements. Event-based sensors offer a potential solution to these challenges. This research centers around a comparative assessment of frame and event-based object detection and tracking. A basic frame-based algorithm is used to compare against two different event-based algorithms. First event-based pseudo-frames were parsed through standard frame-based algorithms and secondly, target tracks were constructed directly from filtered events. The findings show there is significant value in pursuing the technology further.
One-Dimensional Multi-Frame Blind Deconvolution Using Astronomical Data For Spatially Separable Objects,
2020
Air Force Institute of Technology
One-Dimensional Multi-Frame Blind Deconvolution Using Astronomical Data For Spatially Separable Objects, Marc R. Brown
Theses and Dissertations
Blind deconvolution is used to complete missions to detect adversary assets in space and to defend the nation's assets. A new algorithm was developed to perform blind deconvolution for objects that are spatially separable using multiple frames of data. This new one-dimensional approach uses the expectation-maximization algorithm to blindly deconvolve spatially separable objects. This object separation reduces the size of the object matrix from an NxN matrix to two singular vectors of length N. With limited knowledge of the object and point spread function the one-dimensional algorithm successfully deconvolved the objects in both simulated and laboratory data.
Wideband Delay For Solvable Chaos,
2020
University of Alabama in Huntsville
Wideband Delay For Solvable Chaos, Tamseel Mahmood Syed
Research Horizons Day Posters
No abstract provided.
Maximizing Accuracy Through Stereo Vision Camera Positioning For Automated Aerial Refueling,
2020
Air Force Institute of Technology
Maximizing Accuracy Through Stereo Vision Camera Positioning For Automated Aerial Refueling, Kirill A. Sarantsev
Theses and Dissertations
Aerial refueling is a key component of the U.S. Air Force strategic arsenal. When two aircraft interact in an aerial refueling operation, the accuracy of relative navigation estimates are critical for the safety, accuracy and success of the mission. Automated Aerial Refueling (AAR) looks to improve the refueling process by creating a more effective system and allowing for Unmanned Aerial Vehicle(s) (UAV) support. This paper considers a cooperative aerial refueling scenario where stereo cameras are used on the tanker to direct a \boom" (a large, long structure through which the fuel will ow) into a port on the receiver aircraft. …
Handheld Data Analyzer,
2020
Dartmouth College
Handheld Data Analyzer, Nicholas Shade, Jake Herman, Doug Kern, Graham Hazlett, Anita Richardson
ENGS 89/90 Reports
The goal of this project is to design and build a handheld data analyzer prototype paired with an iPad app that our sponsor can further develop into a marketable product. The system should allow technicians to easily collect vibration data from IEPE accelerometers, inspect the data, and upload the reading to our sponsor’s database system for further analysis.
Simulation Of Sporadic-E Parameters Using Phase Screen Method,
2020
Air Force Institute of Technology
Simulation Of Sporadic-E Parameters Using Phase Screen Method, Daniel W. Stambovsky
Theses and Dissertations
A phase screen simulation experiment is designed and implemented to model radio occultation through sporadic-E ionospheric disturbances between a GPS transmitter operating at the L1 frequency and a second receiving satellite in low earth orbit (LEO). Simulations were made to test the linear relationship between plasma intensity and scintillation S4 index both posited (Arras and Wickert, 2018) and contended (Gooch et al., 2020) in previous literature. Results brought into question both the linear relationship and the use of S4 as a whole and an alternate metric was sought.
Heuristic Approaches For Near-Optimal Placement Of Gps-Based Multi-Static Radar Receivers In American Coastal Waters,
2020
Air Force Institute of Technology
Heuristic Approaches For Near-Optimal Placement Of Gps-Based Multi-Static Radar Receivers In American Coastal Waters, Brandon J. Hufstetler
Theses and Dissertations
Narcotics smuggling across the Caribbean Sea is a growing concern for the United States Coast Guard. One vector for this illicit trafficking is via small aircraft. This thesis proposes a multi-static radar architecture using the Global Positioning System (GPS) constellation as a transmission source to detect these aircraft as they transit a detection fence. The system developed in this thesis relies on the forward-scatter phenomenon in which a radar shadow is cast by a target as it crosses in front of a transmitter, creating a measurable difference in the signal amplitude at the receiver. This thesis first develops a mathematical …
Use Of Lidar In Automated Aerial Refueling To Improve Stereo Vision Systems,
2020
Air Force Institute of Technology
Use Of Lidar In Automated Aerial Refueling To Improve Stereo Vision Systems, Michael R. Crowl
Theses and Dissertations
The United States Air Force (USAF) executes five Core Missions, four of which depend on increased aircraft range. To better achieve global strike and reconnaissance, unmanned aerial vehicles (UAVs) require aerial refueling for extended missions. However, current aerial refueling capabilities are limited to manned aircraft due to technical difficulties to refuel UAVs mid-flight. The latency between a UAV operator and the UAV is too large to adequately respond for such an operation. To overcome this limitation, the USAF wants to create a capability to guide the refueling boom into the refueling receptacle. This research explores the use of light detection …
Wireless Sensor Network Optimization For Radio Tomographic Imaging,
2020
Air Force Institute of Technology
Wireless Sensor Network Optimization For Radio Tomographic Imaging, Grant T. Nafziger
Theses and Dissertations
Radio tomographic imaging (RTI) is a form of device-free, passive localization (DFPL) that uses a wireless sensor network (WSN) typically made up of affordable, low-power transceivers. The intent for RTI is to have the ability to monitor a given area, localizing and tracking obstructions within. The specific advantages rendered by RTI include the ability to provide imaging, localization, and tracking where other well developed methods like optical surveillance fall short. RTI can function through optical obstructions such as smoke and even physical obstructions like walls. This provides a tool that is particularly valuable for tactical operations like emergency response and …
Verifying And Improving A Flight Reference System's Performance,
2020
Air Force Institute of Technology
Verifying And Improving A Flight Reference System's Performance, Loren E. Myers
Theses and Dissertations
The 746th Test Squadron (746 TS) at Holloman AFB, NM operates the Ultra High Accuracy Reference System (UHARS) as part of its mission positioning and navigation test. This research presents a method for verifying the performance of a flight reference system using a Delta-Position velocity derived from radio navigation positioning measurements. The algorithm presented may utilize Global Positioning System (GPS) or the Locata ground based positioning system. In the latter case, Locata provides a velocity truth independent from GPS. The accuracy of Locata and GPS are assessed and UHARS velocity measurements are characterized both in nominal and GPS denied applications.
Measuring Localization Confidence For Quantifying Accuracy And Heterogeneity In Single-Molecule Super-Resolution Microscopy,
2020
Washington University in St. Louis
Measuring Localization Confidence For Quantifying Accuracy And Heterogeneity In Single-Molecule Super-Resolution Microscopy, Hesam Mazidi, Tianben Ding, Arye Nehorai, Matthew D. Lew
Electrical & Systems Engineering Publications and Presentations
We present a computational method, termed Wasserstein-induced flux (WIF), to robustly quantify the accuracy of individual localizations within a single-molecule localization microscopy (SMLM) dataset without ground- truth knowledge of the sample. WIF relies on the observation that accurate localizations are stable with respect to an arbitrary computational perturbation. Inspired by optimal transport theory, we measure the stability of individual localizations and develop an efficient optimization algorithm to compute WIF. We demonstrate the advantage of WIF in accurately quantifying imaging artifacts in high-density reconstruction of a tubulin network. WIF represents an advance in quantifying systematic errors with unknown and complex distributions, …
Improved Estimation For Saleh Model And Predistortion Of Power Amplifiers Using 1-Db Compression Point,
2020
Portland State University
Improved Estimation For Saleh Model And Predistortion Of Power Amplifiers Using 1-Db Compression Point, Haider Al Kanan, Xianzhen Yang, Fu Li
Electrical and Computer Engineering Faculty Publications and Presentations
This paper proposes an improved estimation approach for modelling RF power amplifiers (PAs) using the Saleh behavioural model. The proposed approach is appropriate for solid-state PA technologies. The 1-dB compression point of the PA is included in the estimation approach to improve the estimation of the Saleh coefficients. Thus, expressions are derived to describe the relationship between the parameters of the Saleh model and the manufacturing specifications of PAs: gain (G), third-order intercept point (IP3) and 1-dB compression point (P1dB). This method is a simple estimation of a memoryless amplitude-to-amplitude (AM/AM) nonlinearity to benefit RF designers …
A Robust Lpc Filtering Method For Time-Resolved Morphology Of Eeg Activity Analysis,
2020
Technological University Dublin
A Robust Lpc Filtering Method For Time-Resolved Morphology Of Eeg Activity Analysis, Jin Xu, Mark Davis, Ruairí De Fréin
Conference Papers
This paper introduces a new time-resolved spectral analysis method based on Linear Prediction Coding (LPC) method that is particularly suited to the study of the dynamics of EEG (Electroencephalogram) activity. The spectral dynamic of EEG signals can be challenging to analyse as they contain multiple frequency components and are often heavily corrupted by noise. Furthermore, the temporal and spectral resolution that can be achieved is limited by the Heisenberg-Gabor uncertainty principle [1]. The method described here is based on a z-plane analysis of the poles of the LPC which allows us to identify and estimate the frequency of the dominant …
Differential Vector Phase Locked Loop Gps Reception Method,
2020
Air Force Institute of Technology
Differential Vector Phase Locked Loop Gps Reception Method, James Brewer, John F. Raquet
AFIT Patents
A method for enhancing GPS location accuracy includes providing a base station receiver having a known surveyed location, and a roving receiver at a location distinct from the base station receiver. The method further includes receiving single-frequency code and carrier-phase measurements from the base station, and translating the single-frequency code and carrier-phase measurements to a Kalman filter-predicted location of the roving receiver. The translated single frequency code and carrier phase measurements are used to generate a local replica of the Kalman filter-predicted location signals for each channel of the roving receiver. The method further includes correlating the local replicas with …
Mispronunciation Detection And Diagnosis In Mandarin Accented English Speech,
2020
University of Kentucky
Mispronunciation Detection And Diagnosis In Mandarin Accented English Speech, Subash Khanal
Theses and Dissertations--Electrical and Computer Engineering
This work presents the development, implementation, and evaluation of a Mispronunciation Detection and Diagnosis (MDD) system, with application to pronunciation evaluation of Mandarin-accented English speech. A comprehensive detection and diagnosis of errors in the Electromagnetic Articulography corpus of Mandarin-Accented English (EMA-MAE) was performed by using the expert phonetic transcripts and an Automatic Speech Recognition (ASR) system. Articulatory features derived from the parallel kinematic data available in the EMA-MAE corpus were used to identify the most significant articulatory error patterns seen in L2 speakers during common mispronunciations. Using both acoustic and articulatory information, an ASR based Mispronunciation Detection and Diagnosis (MDD) …
Cognitive Resource Management In 5g Networks,
2020
Old Dominion University
Cognitive Resource Management In 5g Networks, Kelvin M. Franco-Argueta
OUR Journal: ODU Undergraduate Research Journal
The 4G LTE network offers a high speed connectivity that is predicated on the construction platform of the 3G network and relies on an Internet Protocol (IP) for data transmission and reception. This platform’s utility is quickly becoming exhausted as the frequency spectrum approaches maximum device connectivity capacity. To improve network capacity, we must expand the bandwidth that our devices operate on. To effectively carry out this task, a self-configurable network must be employed in the development of the 5g network. This article aims to explore the technologies which form the platform for the 5G network and the cognitive resource …
Estimation Of Atmospheric Conditions Over A Long Horizontal Path Using Multi-Frame Blind Deconvolution (Mfbd) Techniques In Comparison With Delayed Tilt Anisoplanatism (Delta) Software,
2020
Michigan Technological University
Estimation Of Atmospheric Conditions Over A Long Horizontal Path Using Multi-Frame Blind Deconvolution (Mfbd) Techniques In Comparison With Delayed Tilt Anisoplanatism (Delta) Software, Hannah Stoll
Dissertations, Master's Theses and Master's Reports
The potential to track and view objects in space from the ground with greater near real time knowledge of the intervening turbulence would be a revolutionary capability. The objective of this thesis is to cross-validate two separate methods used to estimate the Fried parameter. This verification is a step toward a commercial grade product that would make real-time estimates of the turbulence strength along an optical path from a ground-based observatory to a satellite in orbit around the Earth. Michigan Technological University has developed a multi-frame blind deconvolution (MFBD) algorithm used to estimate r0 and it was tested against MZA’s …
