scholarly journals High Dynamic Optimized Carrier Loop Improvement for Tracking Doppler Rates

2015 ◽  
Vol 2015 ◽  
pp. 1-6
Author(s):  
Amirhossein Fereidountabar ◽  
Gian Carlo Cardarilli ◽  
Marco Re
Keyword(s):  
Global Positioning System ◽  
Phase Error ◽  
Low Earth Orbit ◽  
Tracking Loop ◽  
Third Order ◽  
Satellite Systems ◽  
Dynamic Tracking ◽  
Global Positioning ◽  
Tracking Loops ◽  
High Dynamic

Mathematical analysis and optimization of a carrier tracking loop are presented. Due to fast changing of the carrier frequency in some satellite systems, such as Low Earth Orbit (LEO) or Global Positioning System (GPS), or some planes like Unmanned Aerial Vehicles (UAVs), high dynamic tracking loops play a very important role. In this paper an optimized tracking loop consisting of a third-order Phase Locked Loop (PLL) assisted by a second-order Frequency Locked Loop (FLL) for UAVs is proposed and discussed. Based on this structure an optimal loop has been designed. The main advantages of this approach are the reduction of the computation complexity and smaller phase error. The paper shows the simulation results, comparing them with a previous work.

Implementation and Performance Assessment of a Vector Tracking Method Based on a Software GPS Receiver

2011 ◽  
Vol 64 (S1) ◽  
pp. S151-S161 ◽  
Author(s):  
Sihao Zhao ◽  
Mingquan Lu ◽  
Zhenming Feng
Keyword(s):  
Global Positioning System ◽  
Carrier Frequency ◽  
Gps Receiver ◽  
Tracking Loop ◽  
Frequency Tracking ◽  
Tracking Method ◽  
Global Positioning ◽  
Vector Tracking ◽  
Tracking Loops ◽  
And Performance

A number of methods have been developed to enhance the robustness of Global Positioning System (GPS) receivers when there are a limited number of visible satellites. Vector tracking is one of them. It utilizes information from all channels to aid the processing of individual channels to generate receiver positions and velocities. This paper analyzes relationships among code phase, carrier frequency, and receiver position and velocity, and presents a vector loop-tracking algorithm using an Extended Kalman filter implemented in a Matlab-based GPS software receiver. Simulated GPS signals are generated to test the proposed vector tracking method. The results show that when some of the satellites are blocked, the vector tracking loop provides better carrier frequency tracking results for the blocked signals and produces more accurate navigation solutions compared with traditional scalar tracking loops.

Past, present, and future of the technological tracking methods to assess tactical variables in team sports: A systematic review

2020 ◽  
Vol 234 (4) ◽  
pp. 281-290 ◽  
Author(s):  
Markel Rico-González ◽  
José Pino-Ortega ◽  
Fabio Y Nakamura ◽  
Felipe Arruda Moura ◽  
Daniel Rojas-Valverde ◽  
...  
Keyword(s):  
Global Positioning System ◽  
Systematic Reviews ◽  
Team Sports ◽  
Global Navigation Satellite Systems ◽  
Positioning System ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
Global Positioning ◽  
Global Navigation ◽  
Global Navigation Satellite

The main aim of this work was to review the use of technological tracking methods to assess collective spatial-positioning variables in team sports. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and PICO design for systematic reviews, study identification was performed in four databases (PubMed, SPORTDiscus, ProQuest Central, and Web of Science). Articles were selected if they focused on player position and technological tracking methods. After duplicate removal, 2194 articles were identified based on the established search criteria, of which 72 articles were selected and analysed. Semi-automatic optic-based systems, Global Positioning System/Global Navigation Satellite Systems, and local positioning systems were used in 60%, 33% and 7% of the studies, respectively. All studies that measured tactical variables by local positioning system technology in team sports used local position measurement technology. Optic-based systems were used more often in the early years to analyse collective tactical behaviour during competition. Later, Global Positioning System/Global Navigation Satellite Systems became more frequent to measure behaviour in team sports during the training process. The possibility of using the same system during competition and training will facilitate the assessment of collective tactical behaviour in team sports.

GPS Receiver Performance Enhancement via Inertial Velocity Aiding

2001 ◽  
Vol 54 (1) ◽  
pp. 105-117 ◽  
Author(s):  
Dah-Jing Jwo
Keyword(s):  
Performance Enhancement ◽  
Transfer Functions ◽  
Gps Receiver ◽  
Tracking Loop ◽  
Tracking Errors ◽  
Dynamic Tracking ◽  
Tracking Loops ◽  
Receiver Performance ◽  
Velocity Information ◽  
Lock In

An integrated GPS/INS navigation system can employ inertial velocity information to produce a more robust system. For a stand-alone GPS receiver, decreasing the receiver tracking loop bandwidth reduces the probability of losing lock in a jamming or interference environment if vehicle dynamics are low. However, reduced bandwidth increases tracking errors when dynamics are present. Beyond a certain limit, it causes a serious degradation in the dynamic tracking loop performance. Providing inertial velocity aiding to the receiver tracking loops is an effective and popular treatment to help resolve this problem. In this paper, performance of the GPS receiver tracking loops using inertial velocity aiding will be investigated. Different types of tracking loops, from 1st to 3rd order, are covered. Following the discussion of the system architecture and derivation of the related transfer functions for the tracking loops, both with and without aiding, the system performance, including transient response, steady-state error, and noise bandwidth is evaluated.

scholarly journals Galileo: a consolidação do sistema de posicionamento europeu

2020 ◽  
Vol 8 (4) ◽  
pp. 238
Author(s):  
Crislaine Menezes da Silva ◽  
Paulo De Tarso Setti Júnior ◽  
Daniele Barroca Marra Alves ◽  
João Francisco Galera Monico
Keyword(s):  
Global Positioning System ◽  
Global Navigation Satellite Systems ◽  
Positioning System ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
Global Positioning ◽  
Global Navigation ◽  
Global Navigation Satellite

O Galileo é a contribuição da União Europeia ao GNSS (ingl. Global Navigation Satellite Systems – Sistemas de Navegação Global por Satélite) e está próximo da declaração da fase operacional completa, que deve ocorrer no final de 2020 ou início de 2021. Este sistema começou a ser concebido na década de 90, após a decisão do governo americano em não permitir que outras nações participassem da construção e manutenção do sistema NAVSTAR – GPS (ingl. Global Positioning System – Sistema de Posicionamento Global). O sistema Galileo é a primeira contribuição civil para o GNSS e foi desenvolvido de forma a ser independente dos outros sistemas nos segmentos espacial, de controle e operacional. Além disso, está sendo desenvolvido para ser interoperável e compatível com os outros GNSS, em especial o GPS. Nos últimos anos, o desenvolvimento do Galileo fez progressos significativos. A constelação atual compreende um total de 26 satélites orbitando a Terra, 22 operacionais, dos quais três pertencentes à primeira geração de satélites de validação de órbita, e a infraestrutura de controle terrestre está em pleno funcionamento.  Para o usuário, são transmitidos sinais em três frequências E1, E5 e E6. Os sinais em E1 e E5 são transmitidos nas mesmas frequências que os sinais GPS L1 e L5 e ambos sistemas usam princípios de modulação equivalentes. Isso é benéfico pois proporciona uma melhor cobertura e maior robustez para usuários que podem utilizar os sistemas de forma combinada. Além disso, o Galileo oferece vários novos serviços específicos, como o serviço aberto, o serviço de alta acurácia e de busca e resgate. Como o sistema Galileo está atualmente em fase final de implantação, faz-se necessário na literatura brasileira, um artigo que trate exclusivamente desse sistema, este artigo apresenta o estado da arte do sistema Galileo (julho de 2020). Resultados iniciais demonstraram que o Galileo tem acurácia comparável ao GPS, no posicionamento por ponto simples.

scholarly journals Dst Index as a Potential Indicator of Approaching GNSS Performance Deterioration

2012 ◽  
Vol 66 (1) ◽  
pp. 149-160 ◽  
Author(s):  
Renato Filjar ◽  
Serdjo Kos ◽  
Siniša Krajnovic
Keyword(s):  
Global Positioning System ◽  
Mediterranean Area ◽  
Global Navigation Satellite Systems ◽  
Ionospheric Storm ◽  
Satellite Systems ◽  
Dst Index ◽  
Global Positioning ◽  
Potential Indicator ◽  
Performance Deterioration ◽  
Global Navigation Satellite

Space weather disturbances cause considerable effects on Global Navigation Satellite Systems (GNSS) performance and operation, affecting society and the economy due to the growing reliance on GNSS, especially in densely populated mid-latitudes. Recent studies hypothesised potential utilisation of the Disturbance storm-time (Dst) index for indication of an approaching ionospheric storm and possible deterioration of the GNSS positioning performance. We challenged the hypothesis in the case of the Halloween 2003 event in an attempt to confirm the direct correlation between the Dst index dynamics and the Global Positioning System (GPS) positioning performance in the mid-latitude Mediterranean area. Our results provide no evidence of the direct Dst-GNSS performance correlation for the observed event.

GNSS Positioning Enhancement Based on NLOS Multipath Biases Estimation Using Gaussian Mixture Noise

2018 ◽  
Vol 9 (1) ◽  
pp. 21-39 ◽  
Author(s):  
Guermah Bassma ◽  
Sadiki Tayeb ◽  
El Ghazi Hassan
Keyword(s):  
Em Algorithm ◽  
Global Positioning System ◽  
Statistical Tests ◽  
Hybrid Approach ◽  
Gaussian Mixture ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Global Positioning ◽  
Global Navigation Satellite ◽  
Non Line Of Sight

Global navigation satellite systems (GNSS) have been widely used in many applications where positioning plays an important role. However, the performances of these applications can be degraded in urban canyons, due to Non-Line-Of-Sight (NLOS) and Multipath interference affecting GNSS signals. In order to ensure high accuracy positioning, this article proposes to model the NLOS and Multipath biases by Gaussian Mixture noise using Expectation Maximization (EM) algorithm. In this context, an approach to estimate the Multipath and NLOS biases for real time positioning is presented and statistical tests for searching the probability distribution of NLOS and Multipath biases are illustrated. Furthermore, a hybrid approach based on PF (Particle Filter) and EM algorithm for estimating user position in hard environment is presented. Using real GPS (Global Positioning System) signal, the efficiency of the proposed approach is shown, and a significant improvement of the positioning accuracy over the simple PF estimation is obtained.

scholarly journals TRANSLATING AERIAL IMAGES INTO STREET-MAP-LIKE REPRESENTATIONS FOR VISUAL SELF-LOCALIZATION OF UAVS

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 575-580 ◽  
Author(s):  
M. Schleiss
Keyword(s):  
Global Positioning System ◽  
Global Navigation Satellite Systems ◽  
Aerial Imagery ◽  
Aerial Images ◽  
Visual Localization ◽  
Localization Accuracy ◽  
Satellite Systems ◽  
Global Positioning ◽  
Reference Map ◽  
Global Navigation Satellite

<p><strong>Abstract.</strong> Unmanned aerial vehicles (UAVs) rely on global navigation satellite systems (GNSS) like the Global Positioning System (GPS) for navigation but GNSS signals can be easily jammed. Therefore, we propose a visual localization method that uses a camera and data from Open Street Maps in order to replace GNSS. First, the aerial imagery from the onboard camera is translated into a map-like representation. Then we match it with a reference map to infer the vehicle’s position. An experiment over a typical sized mission area shows localization accuracy close to commercial GPS. Compared to previous methods ours is applicable to a broader range of scenarios. It can incorporate multiple types of landmarks like roads and buildings and it outputs absolute positions with higher frequency and confidence and can be used at altitudes typical for commercial UAVs. Our results show that the proposed method can serve as a backup to GNSS systems where suitable landmarks are available.</p>

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