NAVSTAR/GPS — Present Situation and Future Prospects

1982 ◽  
Vol 36 (1) ◽  
pp. 5-8
Author(s):  
J. David Boal
Keyword(s):  
Global Positioning System ◽  
Department Of Defense ◽  
Traffic Management ◽  
Present Situation ◽  
Air Traffic Management ◽  
Satellite System ◽  
Positioning System ◽  
Future Prospects ◽  
Global Positioning ◽  
Resource Exploration

Although the U.S. Department of Defense is developing the NAVSTAR/Global Positioning System (GPS) for its military positioning and navigation requirements, there are obvious civilian benefits to be gained from exploiting this global satellite system. No present navigation system offers the continuous worldwide accuracy in time and position which GPS will deliver. Even now, with only four prototype satellites in operation, GPS users have demonstrated that the accuracy of the system has exceeded design goals. Future applications will include geodynamics, the unification of geodetic datums, surveying, mapping, navigation, hydrography, offshore resource exploration and development, and marine and air traffic management.

The Operational Status of NAVSTAR/GPS

1977 ◽  
Vol 30 (1) ◽  
pp. 35-47 ◽  
Author(s):  
Edward M. Lassiter ◽  
Bradford Parkinson
Keyword(s):  
United States ◽  
Global Positioning System ◽  
Navigation System ◽  
Three Dimensional ◽  
Weather Conditions ◽  
Satellite System ◽  
Positioning System ◽  
Timing Information ◽  
The Earth ◽  
Global Positioning

The NAVSTAR Global Positioning System (GPS) is a satellite-based navigation system that will provide extremely accurate three-dimensional position fixes and timing information to properly equipped users anywhere on or near the Earth. The system will be available continuously regardless of weather conditions and will find extensive utilization in improved weapons delivery accuracies, range instrumentation, &c. Furthermore it will provide an ultimate saving in the number and cost of navigation and position-fixing systems currently employed or projected. It is a Joint Service programme managed by the U.S.A.F. with deputies from the Navy, Army and Marines and the Defense Mapping Agency. The system concept evolved from U.S.A.F. and Navy studies initiated in the mid-1960s. Current programme plans call for the deployment of six satellites in 1977 to permit demonstration and evaluation tests over the continental United States. The system will then be expanded through the deployment of additional satellites into an operational 24-satellite system.

Urban Fleet Monitoring with GPS and GLONASS

1998 ◽  
Vol 51 (3) ◽  
pp. 382-393 ◽  
Author(s):  
M. Tsakiri ◽  
M. Stewart ◽  
T. Forward ◽  
D. Sandison ◽  
J. Walker
Keyword(s):  
Global Positioning System ◽  
Public Transport ◽  
Urban Areas ◽  
Dead Reckoning ◽  
Satellite System ◽  
Basic Function ◽  
Positioning System ◽  
Positioning Systems ◽  
Global Positioning ◽  
Global Navigation Satellite

The increasing volume of traffic in urban areas has resulted in steady growth of the mean driving time on fixed routes. Longer driving times lead to significantly higher transportation costs, particularly for vehicle fleets, where efficiency in the distribution of their transport tasks is important in staying competitive in the market. For bus fleets, the optimal control and command of the vehicles is, as well as the economic requirements, a basic function of their general mission. The Global Positioning System (GPS) allows reliable and accurate positioning of public transport vehicles except within the physical limitations imposed by built-up city ‘urban canyons’. With a view to the next generation of satellite positioning systems for public transport fleet management, this paper highlights the limitations imposed on current GPS systems operating in the urban canyon. The capabilities of a future positioning system operating in this type of environment are discussed. It is suggested that such a system could comprise receivers capable of integrating the Global Positioning System (GPS) and the Russian equivalent, the Global Navigation Satellite System (GLONASS), and relatively cheap dead-reckoning sensors.

Accounting for Inter-System Bias in DGNSS Positioning with GPS/GLONASS/BDS/Galileo

2017 ◽  
Vol 70 (4) ◽  
pp. 686-698 ◽  
Author(s):  
Hui Liu ◽  
Bao Shu ◽  
Longwei Xu ◽  
Chuang Qian ◽  
Rufei Zhang ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Simple Algorithm ◽  
Satellite System ◽  
Harsh Environments ◽  
Positioning System ◽  
Gnss Positioning ◽  
Global Positioning ◽  
System Bias ◽  
Global Navigation Satellite ◽  
Reliability And Availability

Code Differential Global Positioning System (DGPS) is widely used in satellite navigation and positioning because of its simple algorithm and preferable precision. Multi-Global Navigation Satellite System (GNSS) is expected to enhance the accuracy, reliability and availability of Differential GNSS (DGNSS) positioning. Traditional DGNSS models should set separate clock parameters due to the clock differences between the different systems. Awareness of the Inter-System Bias (ISB) could help to maximise the redundancy of the positioning model, thus improving the performance of multi-GNSS positioning. This paper aims to examine the inter-system bias of GPS/GLONASS/BeiDou (BDS)/Galileo and their benefits in DGNSS positioning. Results show that Differential ISB (DISB) characteristics vary with different receiver types and systems. The size of DISB could reach metre-level and the precision of estimated DISBs can reach approximately several centimetres within tens of epochs. Therefore, a new real-time DGNSS model that accounts for ISB is proposed. After differential ISBs are initialised, positioning with four satellites from arbitrarily the same or different systems can be realised. Moreover, compared with the traditional DGNSS model, the precision of the positioning results with the new model are obviously improved, especially in harsh environments.

scholarly journals Comparison of L1 and L5 Bands GNSS Signals Acquisition

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2779 ◽  
Author(s):  
Jérôme Leclère ◽  
René Landry Jr. ◽  
Cyril Botteron
Keyword(s):  
Global Positioning System ◽  
Satellite System ◽  
Positioning System ◽  
Global Positioning ◽  
Accurate Comparison ◽  
The Common ◽  
Parallel Code ◽  
L5 Signal ◽  
Global Navigation Satellite ◽  
Pilot Channel

Nowadays, civil Global Navigation Satellite System (GNSS) signals are available in both L1 and L5 bands. A receiver does not need to acquire independently the signals in both bands coming from a same satellite, since their carrier Doppler and code delay are closely related. Therefore, the question of which one to acquire first rises naturally. Although the common thought would tell the L1 band signals which are narrowband, an accurate comparison has never been done, and the decision is not as easy as it seems. Indeed, L5 band signals have several advantages such as stronger power, lower carrier Doppler, or a pilot channel, unlike the Global Positioning System (GPS) L1 C/A signal. The goal of this paper is therefore to compare the acquisition of L1 and L5 bands signals (GPS L1 C/A and L5, Galileo E1 and E5a/b) to determine which one is more complex and by which factor, in terms of processing time and memory, considering hardware receivers and the parallel code search. The results show that overall the L5 band signals are more complex to acquire, but it depends strongly on the conditions. The E5 signal is always more complex to acquire than E1, while the L5 signal can have a complexity close to the L1 C/A in some cases. Moreover, precise assistance providing accurate Doppler could significantly reduce the L5 complexity below the L1 complexity.

scholarly journals Mapeamento participativo aplicado à Estratégia de Saúde da Família: a experiência em Santo Amaro - BA

2021 ◽  
Vol 73 (2) ◽  
pp. 646-665
Author(s):  
Isabel Cristina Moraes ◽  
Shanti Nitya Marengo ◽  
Gustavo Luís Schacht ◽  
Débora Santos Passos
Keyword(s):  
Global Positioning System ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Google Earth ◽  
Positioning System ◽  
Navigation Satellite ◽  
Global Positioning ◽  
Global Navigation ◽  
Global Navigation Satellite

O acesso a geolocalização em smartphones e tablets tem apontado seu uso potencial no levantamento de dados georreferenciados e como ferramenta de mapeamento replicável por usuários não-especialistas. O objetivo deste artigo é apresentar a experiência do mapeamento participativo dos territórios de ação das equipes de Estratégia de Saúde da Família (ESF) do município de Santo Amaro (BA) com recursos de GPS/GNSS (Global Positioning System/Global Navigation Satellite System) e imagem de satélite do Google Earth, no aplicativo Map Marker. Neste trabalho, são apresentados os aspectos da percepção e transcrição dos elementos espaciais no processo de digitalização e atualização cartográfica destes territórios.  Foram realizadas oficinas nas 17 unidades básicas de saúde (UBS) a fim de cartografar os territórios de atuação – microáreas - dos 104 Agentes Comunitários de Saúde (ACS). Das 17 UBS, 10 apresentavam algum produto cartográfico. Esses produtos pré-existentes contribuíram para a correspondência espacial entre o território e as imagens de satélite. A identificação das microáreas foi satisfatória, porém, o maior desafio foi a vetorização das poligonais. Apesar disso, em cada equipe houve ao menos um profissional que se destacou e foi capaz de reproduzir a metodologia sem um mediador. O uso das tecnologias geoespaciais aplicadas ao mapeamento em saúde mostrou-se viável para a área de estudo, e reforça a importância do treinamento para a autonomia dos atores sociais e a democratização desses recursos nas estratégias em saúde pública. A obtenção destas bases cartográficas deve subsidiar à espacialização de doenças registradas na atenção básica bem como à gestão de saúde do município.

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