scholarly journals GNSS Interference Characterization and Localization Using OpenSky ADS-B Data

Proceedings ◽  
2020 ◽  
Vol 59 (1) ◽  
pp. 10
Author(s):  
Zixi Liu ◽  
Sherman Lo ◽  
Todd Walter
Keyword(s):  
Convex Optimization ◽  
San Francisco ◽  
Source Localization ◽  
Situational Awareness ◽  
San Francisco Bay Area ◽  
Satellite System ◽  
Navigation Satellite ◽  
Bay Area ◽  
Global Navigation Satellite ◽  
The Impact

There is a growing dependence of critical and safety-of-life systems on the Global Navigation Satellite System (GNSS). GNSS interference events can cause severe impacts on aircraft safety, including unavailability of GNSS-based landing services. Therefore, it is important to be able to identify, localize, and remove interference sources that may cause these impacts. This project concentrates on events that affect the the airport environment and aims to provide improved situational awareness and safety for local airspace users. This paper contains three main sections: OpenSky ADS-B data processing, interference event characterization, and interference source localization. Specifically, we identified and removed incorrect timestamps from ADS-B ground receivers. We characterized the impact of interference events based on reported interference events that occurred at a San Francisco bay area airport. In addition, we designed a convex optimization model for localizing the interference sources given the ADS-B measurement. This article looks at common characteristics caused by the impact of interference events and shows a possible way to localize interference sources using ADS-B data.

A Musical Technography of John Bischoff

2004 ◽  
Vol 14 ◽  
pp. 75-79
Author(s):  
Douglas Kahn
Keyword(s):  
San Francisco ◽  
Early Development ◽  
Computer Music ◽  
Turning Point ◽  
San Francisco Bay Area ◽  
Experimental Music ◽  
Music Technology ◽  
Electronic Components ◽  
Bay Area ◽  
The Impact

John Bischoff has been part of the formation and growth of electronic and computer music in the San Francisco Bay Area for over three decades. In an interview with the author, he describes his early development as a student of experimental music technology, including the impact of hearing and assisting in the work of David Tudor. Bischoff, like Tudor, explored the unpredictable potentials within electronic components, and he brought this curiosity to bear when he began working on one of the first available micro-computers. He was a key individual at the historical turning point when computer music escaped its institutional restric-tions and began becoming widespread.

scholarly journals Commuter Response to Traffic Information on an Incident

1998 ◽  
Vol 1621 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Ronald Koo ◽  
Youngbin Yim
Keyword(s):  
San Francisco ◽  
Travel Behavior ◽  
San Francisco Bay Area ◽  
Traffic Information ◽  
Behavior Changes ◽  
Bay Area ◽  
Telephone System ◽  
Changes Over Time ◽  
The Impact ◽  
Insight Into

How traffic information is obtained and how it affects travel behavior when a major freeway is congested are presented and discussed. Immediately following a major highway incident south of San Francisco that caused congestion, a telephone survey was conducted of commuters who use the affected corridor of the highway. The behavior of commuters before and during their commute at the time of the incident was determined, including obtaining traffic information and how the information influenced changes in route, mode of travel, and departure time. The results of the survey suggest that traveler behavior is largely unaffected by individual incidents of congestion. Furthermore, although a fair proportion of commuters do obtain traffic information, they do not often modify their travel behavior in response. This study is one of several that collectively will provide insight into how travel behavior changes over time and allow the authors to assess the impact of TravInfo Traveler Advisory Telephone System in the San Francisco Bay Area.

scholarly journals Testing the Positioning Accuracy of GNSS Solutions during the Tramway Track Mobile Satellite Measurements in Diverse Urban Signal Reception Conditions

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3646 ◽  
Author(s):  
Mariusz Specht ◽  
Cezary Specht ◽  
Andrzej Wilk ◽  
Władysław Koc ◽  
Leszek Smolarek ◽  
...  
Keyword(s):  
Global Navigation Satellite System ◽  
Geodetic Network ◽  
Satellite System ◽  
Railway Vehicle ◽  
Navigation Satellite ◽  
Design Work ◽  
System Solution ◽  
Global Navigation ◽  
Global Navigation Satellite ◽  
The Impact

Mobile Global Navigation Satellite System (GNSS) measurements carried out on the railway consist of using satellite navigation systems to determine the track geometry of a moving railway vehicle on a given route. Their purposes include diagnostics, stocktaking, and design work in railways. The greatest advantage of this method is the ability to perform measurements in a unified and coherent spatial reference system, which effectively enables the combining of design and construction works, as well as their implementation by engineering teams of diverse specialties. In the article, we attempted to assess the impact of using three types of work mode for a GNSS geodetic network [Global Positioning System (GPS), GPS/Global Navigation Satellite System (GLONASS) and GPS/GLONASS/Galileo] on positioning availability at three accuracy levels: 1 cm, 3 cm and 10 cm. This paper presents a mathematical model that enables the calculation of positioning availability at these levels. This model was also applied to the results of the measurement campaign performed by five GNSS geodetic receivers, made by a leading company in the field. Measurements with simultaneous position recording and accuracy assessment were taken separately on the same route for three types of receiver settings: GPS, GPS/GLONASS and GPS/GLONASS/Galileo in an urban area typical of a medium-sized city. The study has shown that applying a two-system solution (GPS/GLONASS) considerably increases the availability of high-precision coordinates compared to a single-system solution (GPS), whereas the measurements with three systems (GPS/GLONASS/Galileo) negligibly increase the availability compared to a two-system solution (GPS/GLONASS).

scholarly journals Impact on Antijamming Performance of Channel Mismatch in GNSS Antenna Arrays Receivers

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Zukun Lu ◽  
Junwei Nie ◽  
Feiqiang Chen ◽  
Gang Ou
Keyword(s):  
Transfer Function ◽  
Global Navigation Satellite System ◽  
Antenna Arrays ◽  
Group Delay ◽  
Satellite System ◽  
Navigation Satellite ◽  
Amplitude Wave ◽  
Channel Mismatch ◽  
Global Navigation Satellite ◽  
The Impact

The performance of antijamming is limited by channel mismatch in global navigation satellite system (GNSS) antenna arrays receivers. Only when the amplitude and phase characteristics of each array channels are the same is the interference likely to be completely suppressed. This paper analyzes the impact on antijamming performance of channel mismatch. We built the model of channel mismatch and derived the impact on transfer function with space-time adaptive processor (STAP) of channel mismatch in theory. The impact factor of channel mismatch is proposed by the fuzzy transfer function, which could directly reflect the antijamming performance under channel mismatch. In addition, every characteristic in the channel mismatch model is analyzed. The analysis results show that the greatest impacts on antijamming performance are the range of amplitude wave and the group delay bias, while the influence of the number of amplitudes is next. As for the effect of group delay fluctuation is the smallest.

scholarly journals Examination Of The Influence Of Service Quality On Membership Renewal In Fitness Centers In San Francisco Bay Area

2010 ◽  
Vol 3 (2) ◽  
Author(s):  
Pei Chih Wei ◽  
Huang-Chia Hung ◽  
Hiu-Chu Yang ◽  
Yu-Jui (Arthur) Hsu ◽  
Zhengwei Ma
Keyword(s):  
Service Quality ◽  
San Francisco ◽  
Service Providers ◽  
San Francisco Bay ◽  
San Francisco Bay Area ◽  
Customer Relationship ◽  
Fitness Centers ◽  
Fitness Center ◽  
Bay Area ◽  
The Impact

Corporations have to learn how to satisfy their customers’ various demands as the era of interactivity with customers has emerged (Pepper & Rogers, 1999). For fitness center, customers’ demands are increasing and diversified. Therefore, service quality is an index of quality assessment from customers for service-producing industries. Furthermore, the concept of corporate expansion and customer relationship has become the foundation of service-providers for higher profitability through customers’ renewal of membership. The main purpose of this study is to evaluate the impact of service quality on the renewal willingness of fitness center membership. Customers from four fitness centers in the San Francisco Bay Area, USA, were randomly selected for this survey. A total of 50 subjects participated in this survey. The data was analyzed by multiple regression and stepwise regression. The result indicated that the service quality has positive influence on the renewal willingness of membership.

Novel sound logger system for sound source localization using global navigation satellite system

2016 ◽  
Vol 140 (4) ◽  
pp. 3062-3062
Author(s):  
Chikao Takasugi ◽  
Keisuke Takeyama ◽  
Takuya Fukaishi ◽  
Yoshikazu Koike ◽  
Harimasa Hojo ◽  
...  
Keyword(s):  
Global Navigation Satellite System ◽  
Source Localization ◽  
Sound Source ◽  
Satellite System ◽  
Sound Source Localization ◽  
Navigation Satellite ◽  
Global Navigation ◽  
Global Navigation Satellite

scholarly journals Situational Awareness: Mapping Interference Sources in Real-Time Using a Smartphone App

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4130 ◽  
Author(s):  
Hong Nguyen ◽  
Micaela Troglia Gamba ◽  
Emanuela Falletti ◽  
Tung Ta
Keyword(s):  
Real Time ◽  
Global Navigation Satellite System ◽  
Situational Awareness ◽  
Satellite System ◽  
Smartphone App ◽  
Navigation Satellite ◽  
The Past ◽  
Global Navigation ◽  
Global Navigation Satellite

In the past years, many techniques have been researched and developed to detect and identify the interference sources of Global Navigation Satellite System (GNSS) signals. In this paper, we utilize a simple and portable application to map interference sources in real-time. The results are promising and show the potential of the crowdsourcing for monitoring and mapping GNSS interference distribution.

scholarly journals Effects of COVID-19 “Sheltering in Place” on Activity in People with Multiple Sclerosis

2020 ◽  
pp. 10.1212/CPJ.0000000000000982
Author(s):  
Valerie J Block ◽  
Riley Bove ◽  
Jeffrey M Gelfand ◽  
Bruce A C Cree
Keyword(s):  
Physical Activity ◽  
Multiple Sclerosis ◽  
San Francisco ◽  
San Francisco Bay Area ◽  
Wearable Technology ◽  
Bay Area ◽  
Neurological Conditions ◽  
Low Levels ◽  
The Impact ◽  
Primary Form

People with neurological conditions that impair mobility such as multiple sclerosis (MS) have low levels of physical activity, with walking their primary form of exercise. When the San Francisco Bay Area shelter-in-place order was announced in mid-March 2020 to flatten the curve of SARS-CoV-2 infections, the abrupt closure of gyms, fitness studios, and malls greatly limited options for safe exercise. We leveraged an ongoing study utilizing wearable technology, to understand the impact of the shelter-in-place policy on physical activity in people with MS (PwMS) at-risk for neurological worsening.

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