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

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.

Sensors ◽  
2019 ◽  
Vol 19 (18) ◽  
pp. 3860 ◽  
Author(s):  
Specht

According to the IHO (International Hydrographic Organization) S-44 standard, hydrographic surveys can be carried out in four categories, the so-called orders—special, 1a, 1b, and 2—for which minimum accuracy requirements for the applied positioning system have been set out. These amount to, respectively: 2 m, 5 m, 5 m, and 20 m at a confidence level of 0.95. It is widely assumed that GNSS (Global Navigation Satellite System) network solutions with an accuracy of 2–5 cm (p = 0.95) and maritime DGPS (Differential Global Positioning System) systems with an error of 1–2 m (p = 0.95) are currently the two main positioning methods in hydrography. Other positioning systems whose positioning accuracy increases from year to year (and which may serve as alternative solutions) have been omitted. The article proposes a method that enables an assessment of any given navigation positioning system in terms of its compliance (or non-compliance) with the minimum accuracy requirements specified for hydrographic surveys. The method concerned clearly assesses whether a particular positioning system meets the accuracy requirements set out for a particular IHO order. The model was verified, taking into account both past and present research results (stationary and dynamic) derived from tests on the following systems: DGPS, EGNOS (European Geostationary Navigation Overlay Service), and multi-GNSS receivers (GPS/GLONASS/BDS/Galileo). The study confirmed that the DGPS system meets the requirements for all IHO orders and proved that the EGNOS system can currently be applied in measurements in the orders 1a, 1b, and 2. On the other hand, multi-GNSS receivers meet the requirements for order 2, while some of them meet the requirements for orders 1a and 1b as well.


2017 ◽  
Vol 70 (4) ◽  
pp. 686-698 ◽  
Author(s):  
Hui Liu ◽  
Bao Shu ◽  
Longwei Xu ◽  
Chuang Qian ◽  
Rufei Zhang ◽  
...  

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.


Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2779 ◽  
Author(s):  
Jérôme Leclère ◽  
René Landry Jr. ◽  
Cyril Botteron

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.


2021 ◽  
Vol 73 (2) ◽  
pp. 646-665
Author(s):  
Isabel Cristina Moraes ◽  
Shanti Nitya Marengo ◽  
Gustavo Luís Schacht ◽  
Débora Santos Passos

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.


1994 ◽  
Vol 47 (2) ◽  
pp. 181-190
Author(s):  
N. Ward

The purpose of the study on which this paper is based was to establish whether there was a maritime requirement for a Global Navigation Satellite System (GNSS) integrity monitoring and warning service in UK and Irish waters, and, if so, how best it could be established and operated.The scope of the study extended to all maritime users: merchant ships; fishing vessels; pleasure craft; and all aspects of the voyage: harbour/harbour approach; coastal and ocean passage.It has been assumed that the United States Global Positioning System (GPS) would be the system adopted, since it is the closest to an operational state. However, most of the technical considerations would apply equally to the Russian GLONASS or any future replacement system under international control.The views expressed are those of the author, and should not be taken to represent the policies of the Department of Transport or any of the other bodies mentioned.


2018 ◽  
Vol 6 (2) ◽  
pp. 155
Author(s):  
Gabriel Oliveira Jerez ◽  
Daniele Barroca Marra Alves

O GPS (Global Positioning System) e o GLONASS (GLObal NAvigation Satellite System) começaram a ser desenvolvidos ainda no início da década de setenta e são, atualmente, os principais sistemas GNSS (Global Navigation Satellite System) com constelação completa disponível. Apesar de os dois sistemas terem obtido constelações completas em períodos próximos, o GLONASS passou por um longo período de degradação, causada principalmente pela falta de investimentos e lançamentos para substituição de satélites mais antigos. Com isso o uso de dados combinados GPS/GLONASS acabou se tornando inviável já no final da década de noventa, devido à instabilidade do GLONASS. Porém, o sistema passou por um processo de modernização e restabelecimento a partir de 2001, obtendo novamente constelação completa de 24 satélites e cobertura global em 2011. A partir dessa nova realidade, novos estudos se fizeram necessário. Nesse sentido o presente trabalho buscou fazer uma revisão dos principais conceitos relacionados ao sistema, bem como do seu histórico, estrutura, além do seu processo de modernização e algumas perspectivas futuras.


2019 ◽  
Vol 94 ◽  
pp. 01019
Author(s):  
Khomsin ◽  
Ira Mutiara Anjasmara ◽  
Danar Guruh Pratomo ◽  
Wahyu Ristanto

Global Navigation Satellite System called GNSS is a term used for the entire global navigation that already operate or are in the planning for the future. Some of the satellite that can be used are GPS (Global Positioning System) operated by USA, GLONASS (Global Navigation Satellite System) operated by Rusia and BeiDou/Compass operated by China. Many errors and biases that occur when measuring with GNSS in the field. Theoritically, there are some errors and biases that can be eliminated or subtracted by strength of satellite geometric. One factor to get a good satellite geometric is to increase the number of satellites received by receiver. In general, the more number of satellites received, the better the geometric satellites received by receivers. The development of receiver technology is currently able to capture GPS, GLONASS and BeiDou signals at one time. Thus the receiver can receive many satellites and finally the shape of geometric satellite becomes better. HiTarget V30 is one of the latest GNSS technology on the market today. This receiver is capable of receiving GPS signals, GLONASS and BeiDou at one time of observation. This research will compare the accuracy of positioning using GPS, GLONASS and BeiDou satellite.


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