Global ETD Search
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Showing 1 to 20 of 22 for “"Satellite systems (GNSS)"”.
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Using Random Sampling Consensus (RANSAC) to Detect Errors in Global Navigation Satellite Systems (GNSS) Signals and Data
… at an identified time. A global navigation satellite system (GNSS) uses the PNT signal to provide satellite-based navigation. Advanced receivers can track multiple GNSS constellations simultaneously. In order to have a robust and accurate solution, a user needs to detect any faulty …
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Using a co-located GNSS radio occultation payload for microwave radiometer calibration
… (RO) instrument with Global Navigation Satellite Systems (GNSS). The radiometer and RO receiver periodically observe the same volume of atmosphere near the earth's limb, allowing for overlapping, or collocated, measurements that can be used to calibrate the radiometer. This method …
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Joint Localization and Synchronization via User Cooperation in Non-Terrestrial Networks
… networks (NTN) with low Earth orbit (LEO) satellites offer a promising alternative for positioning, navigation, and timing (PNT) by providing diversity and increasing the signal-to-noise ratio (SNR) over global navigation satellite systems (GNSS). However, the primary challenge in NTNbased …
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Improving Bluetooth-based Indoor Positioning Using Vision and Artificial Networks
… are increasing continuously. Global Navigation Satellite Systems (GNSS) receivers, while ubiquitous in outdoor positioning, are not effective indoors. One of the best solutions to solve this problem and increase the accuracy of the user's position in indoor areas is to apply other sensors. This …
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Artificial Neural Networks and Map-Matching for GPS Navigation
Global navigation satellite systems (GNSS), such as the Global Positioning System (GPS) have been increasingly used in navigation and tracking of vehicles. Using GPS, certain positioning errors and limitations, such as multipath effects and the geometric position of the satellites (DOP) or signal …
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Design and theoretical analysis of advanced power based positioning in RF system
… for many applications. The global navigation satellite systems (GNSS) is widely used. But its accuracy suffers from signal obstruction by buildings, multipath fading, and disruption due to jamming and spoof. Hence, it is required to supplement GPS with inertial sensors and indoor localization …
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Exploiting Signals of Opportunity for High-Precision PNT: Optimized Bayesian Estimation Across 5G and LEO Networks
… positioning, navigation, and timing (PNT) systems. While traditional global navigation satellite systems (GNSS) degrade severely in deep urban canyons, emerging terrestrial 5G millimeter-wave and non-terrestrial low Earth orbit (LEO) satellite signals of opportunity offer highly promising …
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A subsampling delta-sigma modulator for global navigation satellite systems
Next-generation Global Navigation Satellite Systems (GNSS) receivers should be capable of processing multi-frequency signals in order to provide better positioning accuracy and signal availability to end-user. Nevertheless, the realization of such receivers with conventional receiver architectures …
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Time and Frequency Transfer in a Coherent Multistatic Radar using a White Rabbit Network
… TFT techniques based on global navigation satellite systems (GNSS), have been favoured for several reasons, such as enabling node mobility through wireless operation, geospatial referencing, and atomic clock level time and frequency stability. However, such systems are liable to …
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Advanced Receiver Autonomous Integrity Monitoring for Multi-Constellation GNSS and LEO-Augmented GNSS
Global Navigation Satellite Systems (GNSS), including the U.S. Global Positioning System (GPS), the European Galileo, Russia's GLONASS, and China's BeiDou, have become essential for modern positioning, navigation, and timing (PNT) services, from driving directions to timing in telecommunications. …
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Vehicle autonomy under the Arctic ice: environmental adaptation through model-aided machine learning
… benefit from high-throughput communication systems which enable accurate positioning and operator input; Autonomous Underwater Vehicles (AUVs), however, generally require a higher degree of autonomy as they must rely on much more limited communication links and lack access to global …
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Characterization of the Multipath Environment of Ionospheric Scintillation Receivers
Global Navigation Satellite Systems (GNSS) are used to provide information on position, time and velocity all over the world at any time of the day. Currently there are four operational GNSS and one of them is GPS (Global Positioning System) that is developed and maintained by U.S Department of …
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The Co-Volcanic Ionospheric Disturbances at Mt.Etna, Italy
Global Navigation Satellite Systems (GNSS), originally developed for positioning and navigation, are now widely used for ionospheric sounding. Due to the dispersive nature for radio waves, the ionosphere affects the GNSS signals as a function of its electron density. By this condition the total …
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GNSS-based Hardware-in-the-loop Simulation of Spacecraft Formation Flight: An Incubator for Future Multi-scale Ionospheric Space Weather Studies
… simulation testbeds based on Global-Navigation-Satellite-Systems (GNSS) have been developed to support GNSS-based SFF mission design, however, none of these testbeds has been directly applied to ionospheric space weather studies. The Virginia Tech Formation Flying Testbed (VTFFTB), a GNSS-based …
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Earth Observation Data-Driven Assessment of Local to Regional, Contemporary, and Emerging Coastal Environmental Security Challenges
… significant security challenges to coastal ecosystems, infrastructure, and populations. These dynamic and interacting stressors necessitate continuous monitoring to inform effective mitigation and adaptation strategies. Earth observation data allows for accurate, high-resolution, and continuous …
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GNSS Signal Processing Techniques for Spoofing Resiliency
Global Navigation Satellite Systems (GNSS) for vehicle navigation and timing are widely relied upon by many users in a variety of different sectors such as transit, financial, military, and many others. There are a number of ways for an agent to purposefully degrade a GNSS user's navigation …
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An assessment of archive stereo-aerial photographs for 3-dimensional reconstruction of damaged and destroyed archaeological earthworks
… ground-based collection using Global Navigation Satellite Systems (GNSS) and Terrestrial Laser Scanning (TLS). Empirical differences between these independent data and the SAP DSMs were identified using global statistical measures such as Mean Error (ME), Standard Deviation (SD) and root mean …
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Multi-GNSS real-time precise satellite clock estimation
Nowadays, Global Navigation Satellite Systems (GNSS) play a pivotal role in precise positioning in geosciences and various related domains. Among all GNSS positioning services, real-time precise point positioning (PPP) stands out for its global consistency and flexibility. The quality of real-time …
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Resilient Navigation through Jamming Detection and Measurement Error Modeling
Global Navigation Satellite Systems (GNSS) provide critical positioning, navigation, and timing (PNT) services across various sectors. GNSS signals are weak when they reach Earth from Medium Earth Orbit (MEO), making them vulnerable to jamming. The jamming threat has been growing over the past …
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Radio Propagation Through Density Irregularities in the Auroral Ionosphere
… effects can be detrimental to Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), but the observed effects can be used as a tool to study the underlying plasma process that causes scintillation. Scintillation is commonly seen in equatorial and high-latitude …
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