scholarly journals Analysis of DME/DME Navigation Performance and Ground Network Using Stretched-Front-Leg Pulse-Based DME

Sensors ◽  
2018 ◽  
Vol 18 (10) ◽  
pp. 3275 ◽  
Author(s):  
Euiho Kim
Keyword(s):  
Measuring Equipment ◽  
Federal Aviation Administration ◽  
The United States ◽  
Significant Loss ◽  
Global Navigation Satellite Systems ◽  
Positioning Accuracy ◽  
Satellite Systems ◽  
Ground Station ◽  
Aircraft Navigation ◽  
Global Navigation Satellite

Global navigation satellite systems (GNSS) have become a primary navigation means for aircraft. However, the signal power of GNSS is very weak, and its service can be disrupted at any time when there is interference or jamming. For this reason, the Federal Aviation Administration (FAA) in the United States has recently chosen a distance measuring equipment (DME)-based aircraft navigation technique, called DME/DME, as an alternative aircraft navigation means for use by around 2030. The reason that the FAA plans to use DME/DME in such a short duration, by around 2030, is presumed to be because the ranging accuracy of DMEs is between 70 to 300 m, which is about 7 to 30 times worse than that of GNSS. Thus, a significant loss of positioning performance is unavoidable with current DMEs. To make DME/DME a more competent alternative positioning source, this paper proposes an advanced DME that could provide a ranging accuracy of around 30 m by employing a recently developed Stretched-Front-Leg (SFOL) pulse. The paper introduces optimal ground station augmentation algorithms that help to efficiently transform the current DME ground network to enable a DME/DME positioning accuracy of up to 0.3 nm or 92.6 m with a minimal number of new ground DME sites. The positioning performance and augmented ground network using the proposed SFOL pulse-based DME are evaluated in two regions which have distinct terrain conditions.

How to make a multi-billion dollar thermometer

2021 ◽  
Vol 57 (2) ◽  
pp. 025003
Author(s):  
William H Baird
Keyword(s):  
Positional Information ◽  
The United States ◽  
Global Navigation Satellite Systems ◽  
Physics Students ◽  
Satellite Systems ◽  
Global Positioning ◽  
Field Programmable ◽  
Radio Signals ◽  
Global Navigation Satellite ◽  
Precise Time

Abstract The United States’ Global Positioning System (GPS), and similar geolocation systems such as Galileo, GLONASS, and Beidou are used by people all over the globe. Modern receivers of these global navigation satellite systems can track multiple satellites from different constellations. Casual, non-technical users are probably aware that the positional information provided is typically accurate to within a few meters. We could expect physics students to infer that, because these systems rely on the travel time of radio signals, this implies time measurement accuracy on the scale of tens of nanoseconds. This feature has led to GPS-enabled Internet time servers providing stratum 1 accuracy for under $1000. In this paper, we will show that we can couple a GPS unit to a field programmable gate array (FPGA) to determine the temperature in a room. The more serious application of this GPS-FPGA pairing is to provide precise time-stamping of events, thereby synchronizing data collection between stations across a room or across the globe.

scholarly journals Ionosphere disturbance during cosmodrome “Vostochniy” launches

2018 ◽  
Vol 62 ◽  
pp. 01008
Author(s):  
Zinaida F. Dumbrava ◽  
Vladimir P. Sivokon ◽  
Yuriy A. Teslyuk ◽  
Sergey Y. Khomutov
Keyword(s):  
Acoustic Waves ◽  
Ionospheric Plasma ◽  
Global Navigation Satellite Systems ◽  
Plasma Properties ◽  
Satellite Systems ◽  
Ground Station ◽  
Ionosphere Disturbance ◽  
Global Navigation Satellite ◽  
Carrier Rocket ◽  
Supersonic Motion

It is known that during spacecraft launches ionospheric plasma properties are modified in the result of impact of shock-acoustic waves generated during carrier rocket supersonic motion. As a rule, investigation of ionospheric plasma variations is carried out by the signals of Global Navigation Satellite Systems GPS/GLONASS that implies ground station network. There is no such a system near the “Vostochniy” cosmodrome that makes it necessary to search for an alternative solution. One of them may be the application of ionosphere vertical and oblique sounding stations. Based on the analysis of such station data, the possibility of evaluation of ionosphere modification during “Vostochniy” cosmodrome launches is shown.

Imaging the next Cascadia earthquake: Optimal design for a seafloor GNSS-A network

2021 ◽  
Author(s):  
Eileen L Evans ◽  
Sarah E Minson ◽  
C David Chadwell
Keyword(s):  
Subduction Zone ◽  
Pacific Northwest ◽  
Subduction Zones ◽  
The United States ◽  
Global Navigation Satellite Systems ◽  
Cascadia Subduction Zone ◽  
Satellite Systems ◽  
Concept Of Information ◽  
Outstanding Question ◽  
Global Navigation Satellite

Summary The Cascadia subduction zone in the Pacific Northwest of the United States of America is capable of producing magnitude ∼9 earthquakes, likely often accompanied by tsunamis. An outstanding question in this region, as in most subduction zones, is the degree and spatial extent of strain accumulation, which will eventually release as an earthquake, on the subduction megathrust. Geodetic observations, including those from Global Navigation Satellite Systems (GNSS), may be used to image the strain actively accumulating on a fault before an earthquake ultimately occurs. Technology combining GNSS and underwater acoustic ranging (GNSS-A) is now capable of making centimeter-level horizontal geodetic observations on the seafloor. GNSS-A enables previously inaccessible observations to better image seismogenic portions of the Cascadia subduction zone. Because seafloor geodetic instruments, and the time and logistics associated with observations, can be cost-prohibitive, it is important to identify where deploying seafloor geodetic instruments will provide information that cannot be obtained through a similar investment in onshore geodetic networks. Here we leverage the concept of information entropy to 1) quantify the relative information provided by expanding GNSS observation networks offshore Oregon and Washington and 2) identify optimal locations for a network of seafloor geodetic instruments. The information gained by new observations, and their optimal locations, depends on the expected uncertainties on the seafloor velocity observations, modeling assumptions, and the modeling objectives.

Vulnerability Assessment of the U.S. Transportation Infrastructure that Relies on the Global Positioning System

2003 ◽  
Vol 56 (2) ◽  
pp. 185-193 ◽  
Author(s):  
James V. Carroll
Keyword(s):  
Global Positioning System ◽  
The United States ◽  
Global Navigation Satellite Systems ◽  
Positioning System ◽  
Satellite Systems ◽  
The Public ◽  
Transportation Modes ◽  
Global Positioning ◽  
Global Navigation Satellite ◽  
The U.S

During the course of its development for military use and more recent extension to many civilian uses, vulnerabilities of Global Navigation Satellite Systems (GNSS) – in the United States the Global Positioning System (GPS) – have become apparent. The vulnerabilities arise from natural, intentional, and unintentional sources. Increasing civilian and military reliance on GNSS brings with it a vital need to identify the critical vulnerabilities to civilian users, and to develop a plan to mitigate these vulnerabilities. This paper summarizes the findings of the U.S. Department of Transportation (DOT) vulnerability study that addresses these issues. The key findings are that satellite navigation users are vulnerable to several classes of disruption that affect all transportation modes and related infrastructure; but also that the vulnerabilities can be mitigated by awareness, planning, and using independent backup systems and/or alternate procedures in safety-critical applications. To gain the full benefits of GNSS, it will be necessary to analyse safety-of-life vulnerabilities in detail, and to determine the means and costs of reducing these risks to acceptable levels. The complete assessment report, of which this paper is a synopsis, was released to the public on September 10, 2001. Although the basic findings apply to all GNSS, the assessment focused on the GPS, in response to the enabling Presidential Decision Directive.

Fault Exclusion in Multi-Constellation Global Navigation Satellite Systems

2018 ◽  
Vol 71 (6) ◽  
pp. 1281-1298 ◽  
Author(s):  
Yawei Zhai ◽  
Mathieu Joerger ◽  
Boris Pervan
Keyword(s):  
Upper Bounds ◽  
Global Navigation Satellite Systems ◽  
Service Availability ◽  
Navigation Satellite ◽  
Method Performance ◽  
Satellite Systems ◽  
Aircraft Navigation ◽  
Civil Aircraft ◽  
Global Navigation ◽  
Global Navigation Satellite

This paper comprehensively investigates the fault exclusion problem in multi-constellation Global Navigation Satellite Systems (GNSS). In future GNSS, the heightened likelihood of fault detection events will cause more interruptions in the continuity of the navigation operation. The main contribution of this paper is to establish the theoretical basis to quantify the contributions of fault events on continuity risk, therefore allowing us to assess the desired exclusion function performance based on specific continuity requirements. Accordingly, a new real-time exclusion algorithm is developed, for which the upper bounds on integrity risks are rigorously derived. Using the new method, performance is comprehensively investigated for two important civil aircraft navigation operations using various numbers of constellations. We show that high service availability can be achieved for both operations.

scholarly journals Low-Cost Indoor Positioning Application Based on Map Assistance and Mobile Phone Sensors

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4285 ◽  
Author(s):  
Yi-Shan Li ◽  
Fang-Shii Ning
Keyword(s):  
Mobile Phone ◽  
Indoor Positioning ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Indoor Environments ◽  
Linear Calibration ◽  
Positioning Accuracy ◽  
Satellite Systems ◽  
Global Navigation ◽  
Global Navigation Satellite

Current mainstream navigation and positioning equipment, intended for providing accurate positioning signals, comprise global navigation satellite systems, maps, and geospatial databases. Although global navigation satellite systems have matured and are widespread, they cannot provide effective navigation and positioning services in covered areas or areas lacking strong signals, such as indoor environments. To solve the problem of positioning in environments lacking satellite signals and achieve cost-effective indoor positioning, this study aimed to develop an inexpensive indoor positioning program, in which the positions of users were calculated by pedestrian dead reckoning (PDR) using the built-in accelerometer and gyroscope in a mobile phone. In addition, the corner and linear calibration points were established to correct the positions with the map assistance. Distance, azimuth, and rotation angle detections were conducted for analyzing the indoor positioning results. The results revealed that the closure accuracy of the PDR positioning was enhanced by more than 90% with a root mean square error of 0.6 m after calibration. Ninety-four percent of the corrected PDR positioning results exhibited errors of <1 m, revealing a desk-level positioning accuracy. Accordingly, this study successfully combined mobile phone sensors with map assistance for improving indoor positioning accuracy.

Novel Integrity Concept for CAT III Precision Approaches and Taxiing: Extended GBAS (E-GBAS)

2011 ◽  
Vol 64 (4) ◽  
pp. 695-710 ◽  
Author(s):  
Wolfgang Schuster ◽  
Washington Ochieng
Keyword(s):  
Measurement Errors ◽  
High Performance ◽  
Performance Monitoring ◽  
Global Navigation Satellite Systems ◽  
Monitoring Scheme ◽  
Satellite Systems ◽  
Accuracy Requirement ◽  
Ground Station ◽  
Full Benefit ◽  
Global Navigation Satellite

Future air navigation envisages increased use of Global Navigation Satellite Systems (GNSS) together with advanced communications and surveillance technologies to facilitate the required increase in capacity, efficiency and safety without adversely impacting the environment. The full benefit of GNSS is expected from its ability to support en-route to en-route or gate-to-gate air navigation. This presents challenges particularly for the phases of flight with stringent required navigation performance. Significant work has so far been devoted to the phases of flight up to CAT I. However, more work is required for CAT III precision landing (with an accuracy requirement at the metre level) and taxiing (with an accuracy requirement at sub-metre level) and both with very high integrity and continuity requirements. The main limitation in using GBAS for CAT III landings is the potential decorrelation of the measurement errors between the GBAS ground station (GGS) and the user. The threats in this respect are the atmospheric anomalies. Periods of strong solar activity can cause large local spatial and temporal gradients in the delays induced on the GNSS signals by the ionosphere. The local nature of the effects results in significant decorrelation between GGS measurements and the user. Therefore, a reliable ground based ionospheric anomaly monitoring scheme is required to guarantee integrity.This paper critically reviews state-of-the-art monitors, identifies their limitations and addresses them by proposing a high-performance monitoring scheme for the ionosphere. Preliminary analyses suggest that the proposed scheme has the potential to enable GNSS to meet the navigation requirements for CAT III and taxiing.

Ground-Based Augmentation System Antenna Array Size Reduction via Self-Cardioid Element

2020 ◽  
Vol 35 (10) ◽  
pp. 1228-1235
Author(s):  
James Quinlan ◽  
Daniel Aloi
Keyword(s):  
Antenna Array ◽  
Federal Aviation Administration ◽  
Size Reduction ◽  
Global Navigation Satellite Systems ◽  
Array Size ◽  
Antenna Element ◽  
Navigation Satellite ◽  
Differential Correction ◽  
Satellite Systems ◽  
Global Navigation Satellite

A Ground-Based Augmentation System (GBAS) monitors the signals of Global Navigation Satellite Systems and broadcasts differential correction signals. It relies on Multipath Limiting Antennas (MLAs) that can receive signals over almost the entire upper hemisphere while greatly attenuating signals reflected from the ground. The current Federal Aviation Administration (FAA)-approved system utilizes an MLA that is approximately 182.9 cm tall. In this paper, a substitute MLA is designed that is only 97.05 cm tall (approximately 44% reduction). The size reduction is accomplished by reducing the number of array elements from 19 to 11. We developed a novel self-cardioid antenna element that allows for this reduction.

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