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Global Positioning System

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Full-Text Articles in Physical Sciences and Mathematics

A Light-Weight Technique To Detect Gps Spoofing Using Attenuated Signal Envelopes, Xiao Wei, Muhammad Naveed Aman, Biplab Sikdar Jan 2023

A Light-Weight Technique To Detect Gps Spoofing Using Attenuated Signal Envelopes, Xiao Wei, Muhammad Naveed Aman, Biplab Sikdar

School of Computing: Faculty Publications

Global Positioning System (GPS) spoofing attacks have attracted more attention as one of the most effective GPS attacks. Since the signals from an authentic satellite and the spoofer undergo different attenuation, the captured envelope of fake GPS signals exhibits distinctive transmission characteristics due to short transmission paths. This can be utilized for GPS spoofing detection. The existing technique for GPS spoofing are either computationally too expensive, require specialize hardware/ software updates, or are not accurate enough. To solve these issues, we propose a light-weight GPS spoofing detection method based on a dynamic threshold and captured signal envelope. We validate the …


Gps-Derived Interseismic Fault Locking Along The Jalisco–Colima Segment Of The Mexico Subduction Zone, Beatriz Cosenza-Muralles, Charles Demets, B. Márquez-Azúa, O. Sánchez, J. Stock, Enrique Cabral-Cano, Robert Mccaffrey Apr 2022

Gps-Derived Interseismic Fault Locking Along The Jalisco–Colima Segment Of The Mexico Subduction Zone, Beatriz Cosenza-Muralles, Charles Demets, B. Márquez-Azúa, O. Sánchez, J. Stock, Enrique Cabral-Cano, Robert Mccaffrey

Geology Faculty Publications and Presentations

Northeastward subduction of the oceanic Rivera and Cocos plates in western Mexico poses a poorly understood seismic hazard to the overlying areas of the North America plate. We estimate the magnitude and distribution of interseismic locking along the northern ∼500 km of the Mexico subduction zone, with a series of elastic half-space inversions that optimize the fits to the velocities of 57 GPS stations in western Mexico. All velocities were corrected for the co-seismic, afterslip and viscoelastic rebound effects of the 1995 Colima–Jalisco and 2003 Tecomán earthquakes. We explore the robustness of interseismic locking estimates to a variety of mantle …


Resource Selection Of Deer Hunters In Georgia's Appalachian Mountains, Jacalyn P. Rosenberger, Andrew R. Little, Adam C. Edge, Cheyenne J. Yates, David A. Osborn, Charlie H. Killmaster, Kristina L. Johannsen, Karl V. Miller, Gino J. D'Angelo Mar 2022

Resource Selection Of Deer Hunters In Georgia's Appalachian Mountains, Jacalyn P. Rosenberger, Andrew R. Little, Adam C. Edge, Cheyenne J. Yates, David A. Osborn, Charlie H. Killmaster, Kristina L. Johannsen, Karl V. Miller, Gino J. D'Angelo

School of Natural Resources: Faculty Publications

White‐tailed deer (Odocoileus virginianus) and hunters on 2 Wildlife Management Areas (WMAs) within the Chattahoochee National Forest of northern Georgia, USA, significantly declined in number from the 1980s to 2018. Managers were interested in understanding how they could manipulate hunter distribution according to deer management goals. To understand the spatial distribution of hunting pressure and factors driving hunter resource selection, we analyzed GPS tracking data from 58 deer hunters over the 2018–2019 and 2019–2020 hunting seasons. We evaluated hunter selection on 3 spatial scales relative to elevation, slope, and distance from roads, trails, wildlife openings, deciduous forest, mixed …


Co-Seismic And Post-Seismic Deformation For The 1995 Colima–Jalisco And 2003 Tecoman Thrust Earthquakes, Mexico Subduction Zone, ́ From Modelling Of Gps Data, Beatriz Cosenza-Muralles, Charles Demets, O. Sanchez, Enrique Cabral-Cano, J. Stock, B. Márquez-Azúa, Robert Mccaffrey Mar 2022

Co-Seismic And Post-Seismic Deformation For The 1995 Colima–Jalisco And 2003 Tecoman Thrust Earthquakes, Mexico Subduction Zone, ́ From Modelling Of Gps Data, Beatriz Cosenza-Muralles, Charles Demets, O. Sanchez, Enrique Cabral-Cano, J. Stock, B. Márquez-Azúa, Robert Mccaffrey

Geology Faculty Publications and Presentations

We invert ∼25 yr of campaign and continuous Global Positioning System daily positions at 62 sites in southwestern Mexico to estimate co-seismic and post-seismic afterslip solutions for the 1995 Mw = 8.0 Colima–Jalisco and the 2003 Mw = 7.5 Tecomán earthquakes, and the long-term velocity of each GPS site. Estimates of the viscoelastic effects of both earthquakes from a 3-D model with an elastic crust and subducting slab, and linear Maxwell viscoelastic mantle are used to correct the GPS position time-series prior to our time-dependent inversions. The preferred model, which optimizes the fit to data from several years …


Using Low-Fix Rate Gps Telemetry To Expand Estimates Of Ungulate Reproductive Success, Nathan D. Hooven, Kathleen E. Williams, John T. Hast, Joseph R. Mcdermott, R. Daniel Crank, Gabe Jenkins, Matthew T. Springer, John J. Cox Feb 2022

Using Low-Fix Rate Gps Telemetry To Expand Estimates Of Ungulate Reproductive Success, Nathan D. Hooven, Kathleen E. Williams, John T. Hast, Joseph R. Mcdermott, R. Daniel Crank, Gabe Jenkins, Matthew T. Springer, John J. Cox

Forestry and Natural Resources Faculty Publications

Background

Population parameters such as reproductive success are critical for sustainably managing ungulate populations, however obtaining these data is often difficult, expensive, and invasive. Movement-based methods that leverage Global Positioning System (GPS) relocation data to identify parturition offer an alternative to more invasive techniques such as vaginal implant transmitters, but thus far have only been applied to relocation data with a relatively fine (one fix every  < 8 h) temporal resolution. We employed a machine learning method to classify parturition/calf survival in cow elk in southeastern Kentucky, USA, using 13-h GPS relocation data and three simple movement metrics, training a random forest on cows that successfully reared their calf to a week old.

Results

We developed a decision rule based upon a predicted probability threshold across individual cow time series, accurately classifying 89.5% (51/57) of cows with a known reproductive status. When used to infer status of …


Traditional Knowledge Of Mongolian Pastoralists And Scientific Evidence—A Case Study At A Forest‐Steppe In Northern Mongolia, Yuki Morinaga, T. Ozaki, K. Kakinuma, S. Takatsuki, J. Chuluun Jun 2021

Traditional Knowledge Of Mongolian Pastoralists And Scientific Evidence—A Case Study At A Forest‐Steppe In Northern Mongolia, Yuki Morinaga, T. Ozaki, K. Kakinuma, S. Takatsuki, J. Chuluun

IGC Proceedings (1997-2023)

No abstract provided.


Design And Implementation Of Interactive Ar System For Campus Roaming, Shengwei Qin, Li Zhong, Jinfeng Li, Zihao Chen, Jingqian Ding, Wanshun Liu Dec 2019

Design And Implementation Of Interactive Ar System For Campus Roaming, Shengwei Qin, Li Zhong, Jinfeng Li, Zihao Chen, Jingqian Ding, Wanshun Liu

Journal of System Simulation

Abstract: There are many kinds of navigation applications in universities recently. These applications have obvious shortcomings, which only indicate the outdoor locations without detail information; even some places cannot be found in the map; and it takes a lot of time to design a system. Meanwhile the system cannot achieve real-time interaction effect in virtual ramble. An interactive campus roaming augmented reality (AR) system is designed combining with GPS module for locating outside the campus and utilizing deep learning technology to achieve locating the inside buildings of campus. Simultaneously AR technology will improve interactivity of the system. The experiment …


Forensic Analysis Of A Crash-Damaged Cheerson Cx-20 Auto Pathfinder Drone, Ian N. Mcateer, Peter Hannay, Muhammad I. Malik, Zubair Baig Dec 2018

Forensic Analysis Of A Crash-Damaged Cheerson Cx-20 Auto Pathfinder Drone, Ian N. Mcateer, Peter Hannay, Muhammad I. Malik, Zubair Baig

Journal of Digital Forensics, Security and Law

Long gone are the days when Unmanned Aerial Vehicles (UAVs) and drones (multirotor UAVs) were the exclusive domain of the military for surveillance or tactical strike purposes. For relatively little money mainly due to high-tech progression in microprocessor design, anyone can now purchase a drone with GNSS-tracking capabilities and can support a live high-resolution video feed to its flight controller. The global population of drones has sky- rocketed in recent years as this new technology has been embraced for both its recreational and commercial applications. However, the more nefarious members of society have also recognized the potential for using drones …


Forensic Analysis Of A Crash-Damaged Cheerson Cx-20 Auto Pathfinder Drone, Ian Noel Mcateer, Peter Hannay, Muhammad Imran Malik, Zubair Baig Jan 2018

Forensic Analysis Of A Crash-Damaged Cheerson Cx-20 Auto Pathfinder Drone, Ian Noel Mcateer, Peter Hannay, Muhammad Imran Malik, Zubair Baig

Research outputs 2014 to 2021

Long gone are the days when Unmanned Aerial Vehicles (UAVs) and drones (multirotor UAVs) were the exclusive domain of the military for surveillance or tactical strike purposes. For relatively little money mainly due to high-tech progression in microprocessor design, anyone can now purchase a drone with GNSS-tracking capabilities and can support a live high-resolution video feed to its flight controller. The global population of drones has sky- rocketed in recent years as this new technology has been embraced for both its recreational and commercial applications. However, the more nefarious members of society have also recognized the potential for using drones …


Gnss Augmentation Through Ku-Band Communication Satellites With Rtkrealization, Şenol Gülgönül Jan 2018

Gnss Augmentation Through Ku-Band Communication Satellites With Rtkrealization, Şenol Gülgönül

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a method to broadcast real-time kinematics (RTK) corrections over a communication satellite is proposed. RTK corrections generated by the reference station are uplinked to the communication satellite within a multiplexed DVB-S carrier. Corrections are received by a satellite dish and the DVB-S satellite receiver. Better than 18 cm of accuracy is achieved for rover distances of up to 500 km in Turkey. The proposed method can be used as an alternative satellite-based augmentation system for Turkey and other countries.


Analyzing Glacier Surface Motion Using Lidar Data, Jennifer W. Tellig, Craig Glennie, Andrew G. Fountain, David C. Finnegan Mar 2017

Analyzing Glacier Surface Motion Using Lidar Data, Jennifer W. Tellig, Craig Glennie, Andrew G. Fountain, David C. Finnegan

Geology Faculty Publications and Presentations

Understanding glacier motion is key to understanding how glaciers are growing, shrinking, and responding to changing environmental conditions. In situ observations are often difficult to collect and offer an analysis of glacier surface motion only at a few discrete points. Using light detection and ranging (LiDAR) data collected from surveys over six glaciers in Greenland and Antarctica, particle image velocimetry (PIV) was applied to temporally-spaced point clouds to detect and measure surface motion. The type and distribution of surface features, surface roughness, and spatial and temporal resolution of the data were all found to be important factors, which limited the …


Applications Of Satellite Geodesy In Environmental And Climate Change, Qian Yang May 2016

Applications Of Satellite Geodesy In Environmental And Climate Change, Qian Yang

USF Tampa Graduate Theses and Dissertations

Satellite geodesy plays an important role in earth observation. This dissertation presents three applications of satellite geodesy in environmental and climate change. Three satellite geodesy techniques are used: high-precision Global Positioning System (GPS), the Gravity Recovery and Climate Experiment (GRACE) and Interferometric Synthetic Aperture Radar (InSAR). In the first study, I use coastal uplift observed by GPS to study the annual changes in mass loss of the Greenland ice sheet. The data show both spatial and temporal variations of coastal ice mass loss and suggest that a combination of warm atmospheric and oceanic condition drove these variations. In the second …


Where Am I? Characterizing And Improving The Localization Performance Of Off-The-Shelf Mobile Devices Through Cooperation, Huiguang Liang, Hyong S. Kim, Hwee-Pink Tan, Wai-Leong Yeow Apr 2016

Where Am I? Characterizing And Improving The Localization Performance Of Off-The-Shelf Mobile Devices Through Cooperation, Huiguang Liang, Hyong S. Kim, Hwee-Pink Tan, Wai-Leong Yeow

Research Collection School Of Computing and Information Systems

We are increasingly reliant on cellular data services for many types of day-to-day activities, from hailing a cab, to searching for nearby restaurants. Geo-location has become a ubiquitous feature that underpins the functionality of such applications. Network operators can also benefit from accurate mobile terminal localization in order to quickly detect and identify location-related network performance issues, such as coverage holes and congestion, based on mobile measurements. Current implementations of mobile localization on the wildly-popular Android platform depend on either the Global Positioning System (GPS), Android's Network Location Provider (NLP), or a combination of both. In this paper, we extensively …


Effect Of Grazing Prairie Dog—Colonized Rangeland On Cattle Nutrition And Performance: A Progress Report, Kenneth C. Olson, Christopher Schauer, Chanda Engel, Janna J. Kincheloe, Jameson R. Brennan, Ben L. Hauptman Feb 2016

Effect Of Grazing Prairie Dog—Colonized Rangeland On Cattle Nutrition And Performance: A Progress Report, Kenneth C. Olson, Christopher Schauer, Chanda Engel, Janna J. Kincheloe, Jameson R. Brennan, Ben L. Hauptman

Natural Resource Management Faculty Publications

On the Ground

  • One objective of the ongoing Renewal on Standing Rock Reservation project is to evaluate the response of grazing steers to the level of prairie dog colonization on Northern Mixed Grass Prairie.
  • We fenced four pastures to create an increasing gradient of a proportion of the pasture area colonized by prairie dogs. Pastures are stocked with yearling steers during each growing season.
  • Comparing steer performance, Global Positioning System (GPS) locations of grazing, diet samples, and ingestive behavior at each proportion of the prairie dog colony per pasture allows prediction of the optimal proportion of colonization, which enables selection …


On Neighborhood Effects In Location-Based Social Networks, Thanh-Nam Doan, Freddy Chong-Tat Chua, Ee-Peng Lim Dec 2015

On Neighborhood Effects In Location-Based Social Networks, Thanh-Nam Doan, Freddy Chong-Tat Chua, Ee-Peng Lim

Research Collection School Of Computing and Information Systems

In this paper, we analyze factors that determine the check-in decisions of users on venues using a location-based social network dataset. Based on a Foursquare dataset constructed from Singapore-based users, we devise a stringent criteria to identify the actual home locations of a subset of users. Using these users' check-ins, we aim to ascertain the neighborhood effect on the venues visited, compared with the activity level of users. We further formulate the check-in count prediction and check-in prediction tasks. A comprehensive set of features have been defined and they encompass information from users, venues, their neighbors, and friendship networks. We …


Current State Of Strain In The Central Cascadia Margin Derived From Changes In Distance Between Gps Stations, Kenneth M. Cruikshank, Curt D. Peterson Feb 2015

Current State Of Strain In The Central Cascadia Margin Derived From Changes In Distance Between Gps Stations, Kenneth M. Cruikshank, Curt D. Peterson

Geology Faculty Publications and Presentations

Using continuously operating Global Positioning Stations in the Pacific Northwest of the United States, over 100 station-station baseline length changes were determined along seven West-East transects, two North-South transects and in three localized areas to determine both the average annual strains over the past several years, and the variation in strain over the central Cascadia convergent margin. The North-South transects (composed of multiple baselines) show shortening. Along West-East transects some baselines show shortening and others extension. The direction of the principle strains calculated for two areas 100 km from the deformation front are close to per-pendicular to the deformation front. …


Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez Dec 2014

Earthquake And Tsunami Forecasts: Relation Of Slow Slip Events To Subsequent Earthquake Rupture, Timothy H. Dixon, Yan Jiang, Rocco Malservisi, Robert Mccaffrey, Nicholas Voss, Marino Protti, Victor Gonzalez

Geology Faculty Publications and Presentations

The 5 September 2012 Mw 7.6 earthquake on the Costa Rica subduction plate boundary followed a 62-y interseismic period. High-precision GPS recorded numerous slow slip events (SSEs) in the decade leading up to the earthquake, both up-dip and down-dip of seismic rupture. Deeper SSEs were larger than shallower ones and, if characteristic of the interseismic period, release most locking down-dip of the earthquake, limiting down-dip rupture and earthquake magnitude. Shallower SSEs were smaller, accounting for some but not all interseismic locking. One SSE occurred several months before the earthquake, but changes in Mohr–Coulomb failure stress were probably too small to …


Gps Constraints On The Mw = 7.5 Ometepec Earthquake Sequence, Southern Mexico: Coseismic And Post-Seismic Deformation, Shannon E. Graham, Charles Demets, Enrique Cabral-Cano, Vladimir Kostoglodov, Andrea Walpersdorf, Nathalie Cotte, Michael Brudzinski, Robert Mccaffrey, Luis Salazar-Tlaczani Oct 2014

Gps Constraints On The Mw = 7.5 Ometepec Earthquake Sequence, Southern Mexico: Coseismic And Post-Seismic Deformation, Shannon E. Graham, Charles Demets, Enrique Cabral-Cano, Vladimir Kostoglodov, Andrea Walpersdorf, Nathalie Cotte, Michael Brudzinski, Robert Mccaffrey, Luis Salazar-Tlaczani

Geology Faculty Publications and Presentations

We use continuous GPS measurements from 31 stations in southernMexico to model coseismic slip and post-seismic deformation from the 2012 March 20 Mw = 7.5 Ometepec earthquake, the first large thrust earthquake to occur below central Mexico during the modern GPS era. Coseismic offsets ranging from ∼280 mm near the epicentre to 5 mm or less at sites far from the epicentre are fit best by a rupture focused between ∼15 and 35 km depth, consistent with an independent seismological estimate. The corresponding geodetic moment of 1.4 × 1020 N·m is within 10 per cent of two independent seismic …


Evolution Of The Stress And Strain Fields In The Eastern Cordillera, Colombia, Obi Egbue, James N. Kellogg Dec 2013

Evolution Of The Stress And Strain Fields In The Eastern Cordillera, Colombia, Obi Egbue, James N. Kellogg

James N Kellogg

This work integrates stress data from Global Positioning System measurements and earthquake focal mechanism solutions, with new borehole breakout and natural fracture system data to better understand the complex interactions between the major tectonic plates in northwestern South America and to examine how the stress regime in the Eastern Cordillera and the Llanos foothills in Colombia has evolved through time. The dataset was used to generate an integrated stress map of the northern Andes and to propose a model for stress evolution in the Eastern Cordillera. In the Cordillera, the primary present-day maximum principal stress direction is WNW-ESE to NW-SE, …


Compression Of Gps Trajectory Data : Benchmarking Framework And New Approach, Jonathan Muckell Jan 2013

Compression Of Gps Trajectory Data : Benchmarking Framework And New Approach, Jonathan Muckell

Legacy Theses & Dissertations (2009 - 2024)

GPS-equipped mobile devices such as smart phones and in-car navigation units are collecting enormous amounts of spatial and temporal information that traces a moving object's path. The exponential increase in the amount of such trajectory data has caused three major problems. First, transmission of large amounts of data is expensive and time-consuming. Second, queries on large amounts of trajectory data require computationally expensive operations to extract useful patterns and information. Third, GPS trajectories often contain large amounts of redundant data that waste storage and cause increased disk I/O time. These issues can be addressed by algorithms that reduce the size …


Wifipoz -- An Accurate Indoor Positioning System, Xiaoyi Ye Jan 2012

Wifipoz -- An Accurate Indoor Positioning System, Xiaoyi Ye

EWU Masters Thesis Collection

"Location based services are becoming an important part of life. Wide adoption of GPS in mobile devices combined with cellular networks has practically solved the problem of outdoor localization needs. The problem of locating an indoor user has being studied only recently. Much research contributed to the innovative concept of an indoor positioning system. By analyzing different technologies and algorithms, this thesis concluded that, considering a trade-off between accuracy and cost, a Wi-Fi based Fingerprint method is proved to be the most promising approach to determine the location of a mobile device. However, the Fingerprint method works in two phases-an …


A Global Positioning System On The Lunar Sphere Utilizing Cubesats, Armani Giann Batista Jan 2012

A Global Positioning System On The Lunar Sphere Utilizing Cubesats, Armani Giann Batista

Theses Digitization Project

The purpose of this thesis was to research the viability and feasibility of a new Lunar GPS that would utilize the CubeSat platform, newly emerging technology, and the consideration of satellites without the large, currently employed, chemically atomic clocks.


Gobuddy - Android Mobile Application, Kalaivani Nellaiappan Jan 2011

Gobuddy - Android Mobile Application, Kalaivani Nellaiappan

Theses Digitization Project

The purpose of this application is to serve the end user of an Android Smart phone, with reliable, instantaneous and location based information on places of interest such as restaurants, gas stations, hotels, movie theaters, and the like by using the phones' built-in GPS. The basic information includes viewing the map and address of the place of interest and getting the directions to a particular place in addition to having some extra features. Contains computer source code.


Satellite Navigation Forensics Techniques, Peter Hannay Mar 2009

Satellite Navigation Forensics Techniques, Peter Hannay

Australian Digital Forensics Conference

Satellite navigation systems are becoming increasingly common for automotive use within the civilian population. This increase in use is of interest to forensic investigators as satellite navigation devices have the potential to provide historical location data to investigators. The research in progress investigates the data sources and encoding on a number of common satellite navigation devices. The aim of this research is to develop a framework for the acquisition and analysis of common satellite navigation systems in a way that valid for multiple device


Forensic Acquisition And Analysis Of The Tomtom One Satellite Navigation Unit, Peter Hannay Mar 2008

Forensic Acquisition And Analysis Of The Tomtom One Satellite Navigation Unit, Peter Hannay

Australian Digital Forensics Conference

Global Positioning Systems are becoming increasingly pervasive. The forensic acquisition and analysis of these units is of great interest as it has the potential to yield historic locational data for these units. Analysis of the TomTom one satellite navigation unit has resulted in a method to reliably extract historic data from these devices in a forensically sound manner.


Efficient Gps Position Determination Algorithms, Thao Nguyen Jun 2007

Efficient Gps Position Determination Algorithms, Thao Nguyen

Theses and Dissertations

This research is aimed at improving the state of the art of GPS algorithms, namely, the development of a closed-form positioning algorithm for a standalone user and the development of a novel differential GPS algorithm for a network of users. The stand-alone user GPS algorithm is a direct, closed-form, and efficient new position determination algorithm that exploits the closed-form solution of the GPS trilateration equations and works in the presence of pseudorange measurement noise for an arbitrary number of satellites in view. A two-step GPS position determination algorithm is derived which entails the solution of a linear regression and updates …


Holes: Ionospheric Scintillation, Gps And Imputation, Robert A. Steenburgh Mar 2007

Holes: Ionospheric Scintillation, Gps And Imputation, Robert A. Steenburgh

Theses and Dissertations

Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active, although not limited to, a belt encircling the earth within ± 20 degrees of the geomagnetic equator. This belt also hosted roughly half of the completed U.S. military operations in the last decade. The authors examined scintillation data from Ascension Island, United Kingdom, and Ancon, Peru, in the Atlantic longitudinal sector as well as data from Parepare, Indonesia, and Marak Parak, Malaysia, in the Pacific longitudinal sector. From these data, they calculate percent probability of occurrence …


Wireless Indoor Positioning System With Enhanced Nearest Neighbors In Signal Space Algorithm, Quang Tran, Juki Wirawan Tantra, Ah-Hwee Tan, Ah-Hwee Tan, Kin-Choong Yow, Dongyu Qiu Sep 2006

Wireless Indoor Positioning System With Enhanced Nearest Neighbors In Signal Space Algorithm, Quang Tran, Juki Wirawan Tantra, Ah-Hwee Tan, Ah-Hwee Tan, Kin-Choong Yow, Dongyu Qiu

Research Collection School Of Computing and Information Systems

With the rapid development and wide deployment of wireless Local Area Networks (WLANs), WLAN-based positioning system employing signal-strength-based technique has become an attractive solution for location estimation in indoor environment. In recent years, a number of such systems has been presented, and most of the systems use the common Nearest Neighbor in Signal Space (NNSS) algorithm. In this paper, we propose an enhancement to the NNSS algorithm. We analyze the enhancement to show its effectiveness. The performance of the enhanced NNSS algorithm is evaluated with different values of the parameters. Based on the performance evaluation and analysis, we recommend some …


Development And Testing Of A High-Speed Real-Time Kinematic Precise Dgps Positioning System Between Two Aircraft, Christopher J. Spinelli Sep 2006

Development And Testing Of A High-Speed Real-Time Kinematic Precise Dgps Positioning System Between Two Aircraft, Christopher J. Spinelli

Theses and Dissertations

This research involves the design, implementation, and testing of a high-speed, real-time kinematic, precise differential GPS positioning system for use in airborne applications such as automated aerial-refueling and close formation flying. Although many of the current ambiguity resolution techniques use the residuals from the least squares position estimation to determine the true ambiguity set, this thesis presents a novel approach to the ambiguity resolution problem, called the minimum indicator. Instead of assuming the ambiguity set with the lowest residuals is the true set, other special characteristics of the residuals are examined. This increases the confidence that the algorithm has selected …


A Climatological Study Of Equatorial Gps Data And The Effects On Ionospheric Scintillation, Katharine A. Wicker Mar 2006

A Climatological Study Of Equatorial Gps Data And The Effects On Ionospheric Scintillation, Katharine A. Wicker

Theses and Dissertations

Ionospheric scintillation is detrimental to radio signals, especially those from the global positioning system. Such scintillation is caused when a signal permeates the ionosphere through plasma bubbles. The signal’s phase and amplitude can be altered, and a receiver on the ground can lose lock on the GPS signal. Measured using a zero to one index known as S4, scintillation severity is based upon season, solar cycle, time of day, location and frequency. The most severe scintillation occurs at the equatorial anomaly, or fifteen degrees north and south of the equator. Seven years of data from fifteen different locations around the …