scholarly journals Análise de modelos troposféricos no posicionamento baseado em redes usando o conceito de VRS

2014 ◽  
Vol 20 (1) ◽  
pp. 39-53 ◽  
Author(s):  
Adeliton Da Fonseca De Oliveira ◽  
Daniele Barroca Marra Alves ◽  
Luiz Danilo Damasceno Ferreira
Keyword(s):  
Global Positioning System ◽  
Reference Station ◽  
Positioning System ◽  
Virtual Reference ◽  
Global Positioning

Nos últimos anos, várias técnicas de posicionamento GPS (Global Positioning System) vêm sendo desenvolvidas e/ou aprimoradas com interesse de alcançar alta acurácia e produtividade em tempo real. O conceito de redes de estações de referência além de possibilitar aos usuários das comunidades civis e científicas qualidade e confiabilidade no posicionamento, permite estudos sobre a modelagem da refração troposférica na região da rede. Além disso, dentre as formas de transmissão das correções geradas pela rede ao usuário, destaca-se o conceito de VRS (Virtual Reference Station). Neste método, os dados de uma estação virtual são gerados nas proximidades do usuário, permitindo realizar posicionamento relativo em linhas de base curta com receptor de simples frequência. Neste artigo é descrita a metodologia para geração de dados da VRS com diferentes modelos troposféricos. Foram realizados testes comparativos nas quatro estações do ano com os modelos troposféricos de PNT/INPE (Previsão Numérica de Tempo/Instituto Nacional de Pesquisas Espaciais) e Hopfield. Na análise de qualidade dos dados da VRS, o método PPP (Posicionamento por Ponto Preciso) proporcionou resultados satisfatórios. Foram observadas melhorias entre os modelos de PNT/INPE e Hopfield de 9,75% e 24,2% em média para dias secos e úmidos, respectivamente.

scholarly journals Investigation of accurate method in 3-D position using Cors-Net in Istanbul

2012 ◽  
Vol 18 (2) ◽  
pp. 171-184 ◽  
Author(s):  
Kutalmis Gumus ◽  
Cahit Tagi Celik ◽  
Halil Erkaya
Keyword(s):  
Real Time ◽  
Conventional Method ◽  
Global Positioning System ◽  
Complex Structure ◽  
Accurate Method ◽  
Reference Station ◽  
Positioning System ◽  
Virtual Reference ◽  
Global Positioning ◽  
Set Up

In this study, for Istanbul, there are two Cors Networks (Cors-TR, Iski Cors) providing Virtual Reference Station (VRS), and Flachen Korrektur Parameter (FKP), corrections to rover receiver for determining 3-D positions in real time by Global Positioning System (GPS). To determine which method (or technique) provides accurate method for position fixing, a test network consisting of 49 stations was set up in Yildiz Technical University Davudpasa Campus. The coordinates of the stations in the test network were determined by conventional geodetic, classical RTK, VRS and FKP methods serviced by both Cors-TR and Iski Cors. The results were compared to the coordinates by the conventional method by using total station. The results showed a complex structure as the accuracy differs from one component to another such as in horizontal coordinates, Y components by CorsTR_VRS and Cors_TR_ FKP showed 'best' results while the same technique provided X components consistent accuracy with the Y component but less accurate than by real time kinematic (RTK). In vertical components, of all the techniques used for the h components, CorsTR_VRS showed 'best' accuracy with three outliers.

scholarly journals Posicionamento GNSS em Tempo Real: Evolução, Aplicações Práticas e Perspectivas para o Futuro

2020 ◽  
Vol 72 ◽  
pp. 1359-1379
Author(s):  
Claudia Pereira Krueger ◽  
Paulo Sérgio de Oliveira Junior ◽  
Silvio Jacks dos Anjos Garnés ◽  
Daniele Barroca Marra Alves ◽  
Jorge Felipe Euriques
Keyword(s):  
Real Time ◽  
Global Positioning System ◽  
Precise Point Positioning ◽  
Reference Station ◽  
Space Representation ◽  
Positioning System ◽  
Differential Gps ◽  
Virtual Reference ◽  
State Space Representation ◽  
Global Positioning

O posicionamento em tempo real por meio do emprego dos sinais de satélites foi um avanço nas navegações aérea, marítima e terrestre com o surgimento do GPS (Global Positioning System). Contudo as precisões horizontais e verticais de 100 m e 150 m (nível de probabilidade de 95%) alcançadas, estando a SA (Selective Availability) ativada, passaram a não ser satisfatórias para muitas aplicações e os usuários buscaram galgar outros níveis de precisões. Esforços foram investidos no chamado posicionamento diferencial DGPS (Differential GPS), o qual possibilitou obter precisões em torno de dez vezes melhores do que as do posicionamento absoluto.  Posteriormente, usando-se a fase da onda portadora, conseguiu-se realizar posicionamento com maior acurácia por meio do método RTK (Real Time Kinematic), atingindo qualidade centimétrica. Na sequência, houve uma evolução para posicionamentos em rede, empregando, por exemplo, o algoritmo de VRS (Virtual Reference Station). Vários erros nas observáveis dos satélites passaram a ser modelados com uma solução de multiestações em tempo real. A partir de 2012, surgiram serviços e produtos que favoreceram o desenvolvimento do RT-PPP (Real-Time Precise Point Positioning) baseado no conceito SSR (State Space Representation). A busca da solução das ambiguidades no RT-PPP deu origem ao PPP-RTK com menor tempo de fixação das ambiguidades e convergência para a solução acurada do posicionamento. Neste artigo apresenta-se como foi a evolução do posicionamento em tempo real, algumas das aplicações no âmbito nacional e as perspectivas  desta modalidade de posicionamento para o futuro.

scholarly journals Accuracy Analysis of Aircraft Position at Departure Phase Using DGPS Method

2020 ◽  
Vol 14 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Kamil Krasuski ◽  
Janusz Ćwiklak
Keyword(s):  
Global Positioning System ◽  
Vertical Plane ◽  
Flight Test ◽  
Reference Station ◽  
Civil Aviation ◽  
Positioning System ◽  
Technical Standards ◽  
Mean Values ◽  
Global Positioning ◽  
Differential Corrections

AbstractThe aim of this paper is to present the problem of implementation of the Differential Global Positioning System (DGPS) technique in positioning of the aircraft in air navigation. The aircraft coordinates were obtained based on Global Positioning System (GPS) code observations for DGPS method. The DGPS differential corrections were transmitted from reference station REF1 to airborne receiver using Ultra High Frequency (UHF) radio modem. The airborne Thales Mobile Mapper receiver was mounted in the cabin in Cessna 172 aircraft. The research test was conducted around the military aerodrome EPDE in Dęblin in Poland. In paper, the accuracy of aircraft positioning using DGPS technique is better than 1.5 m in geocentric XYZ frame and ellipsoidal BLh frame, respectively. In addition, the obtained accuracy of aircraft positioning is in agreement with International Civil Aviation Organization (ICAO) Required Navigation Performance (RNP) technical standards for departure phase of aircraft. The presented research method can be utilised in Ground-Based Augmentation System (GBAS) in air transport. In paper, also the accuracy results of DGPS method from flight test in Chełm are presented. The mean values of accuracy amount to ±1÷2 m for horizontal plane and ±4÷5 m for vertical plane.

Spatial and Seasonal Ionospheric Error Growth in DGPS Measurement: A Case Study in Malaysia

2015 ◽  
Vol 68 (6) ◽  
pp. 1105-1119
Author(s):  
W.A. Wan Aris ◽  
T.A. Musa ◽  
W.H. Ooi ◽  
A. Hairizam ◽  
I.A. Musliman ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Regression Model ◽  
Global Positioning System ◽  
Solar Maximum ◽  
Equatorial Ionosphere ◽  
Reference Station ◽  
Positioning System ◽  
Error Growth ◽  
Global Positioning

This paper tackles the Equatorial ionosphere and its effects on Differential Global Positioning System (DGPS) error growth over Malaysia by using a network of GPS Continuously Operating Reference Stations (CORS). Seasonal variation of ionospheric delay has been examined and findings show that the effect of spatial variation of ionospheric errors in DGPS is very significant during the equinoctial seasons. Furthermore, a DGPS regression model was developed and tested during the solar maximum year in 2013 by using internet-based DGPS. The results show that the model is capable of estimating DGPS positional errors for distances of user to reference station less than 680 km.

scholarly journals Outdoor Localisation for Navigation Tracking using Differential Global Positioning System Estimation (DGPS) : Positioning Errors Analysis

Mekatronika ◽  
2019 ◽  
Vol 1 (2) ◽  
pp. 103-114
Author(s):  
Wi Kang Chew ◽  
Muhammad Aizzat Zakaria
Keyword(s):  
Global Positioning System ◽  
Autonomous Vehicles ◽  
Reference Station ◽  
Positioning System ◽  
Positioning Accuracy ◽  
Dilution Of Precision ◽  
Positioning Errors ◽  
Global Positioning ◽  
Errors Analysis ◽  
Differential Global Positioning System

Global Positioning System (GPS) is a very popular outdoor positioning system. Due to the satellites’ errors signal, the Global Positioning System (GPS) receivers determine the accuracy of a current location with about 100 meters in latitude and 156 meters in longitude. In this few years, the technology on autonomous vehicles is rising. Autonomous vehicles need to navigate with high positioning accuracy for preventing any potential danger to road user. So in this paper, Differential Global Positioning System (DGPS) experiment will be introduced for improve the positioning accuracy. Differential Global Positioning System (DGPS) operations compose of Reference Station and Rover Station. Both of the station will use the GPS receiver for receiving the positioning data from GPS satellites and the positioning data collected from Reference Station will be used to calculate the positioning errors and the errors correction will then be transferred to Rover Station to improve the positioning accuracy. The results obtained will be discussed based on the average and range of errors in both latitude and longitude, number of satellites detected, Horizontal Dilution of Precision (HDOP), Vertical Dilution of Precision (VDOP) and the improvement on Differential Global Positioning System (DGPS) at the same time in different day. In four days’ results, it can be seen that the number of satellites detected will be affected by the Horizontal Dilution of Precision (HDOP) and Vertical Dilution of Precision (VDOP) which cause the positioning errors in latitude and longtitude. The average of positioning errors range between -4.165m and 2.925m in latitude and -0.618m and 1.998m in longitude.

Analysis of NRC-Net Global Positioning System-Derived Velocity Vectors for Tectonic Movement in Malaysia

2020 ◽  
Vol 17 (2) ◽  
pp. 1292-1301
Author(s):  
Nini Nurdiana Johari ◽  
Tajul Ariffin Musa ◽  
Usmuni Din ◽  
Wan Anom Wan Aris
Keyword(s):  
Global Positioning System ◽  
Reference Station ◽  
Positioning System ◽  
Least Squares Regression ◽  
Tectonic Movement ◽  
Linear Least Squares ◽  
Residual Velocity ◽  
Tectonic Model ◽  
Global Positioning ◽  
Gps Observation

This paper seeks to estimate the velocity vectors of National Research and Development (R&D) Continuously Operating Reference Station (CORS) network (NRC-net) by utilizing Global Positioning System (GPS) observation spanning the period of the year 2013–2016. Currently, the NRC-net consists of twenty (20) permanent, widely distributed stations which have been operated continuously since 2009 over Malaysia. In this paper, GPS data were processed and presented in terms of coordinate time series to estimate the velocity vectors by employing linear least squares regression which able to portray the general overview on the tectonic movement of the Malaysia region. Up component shows vertical velocity of less than 1.00 cm/year while both north and east components were further analyzed with respect to MORVEL 2010 tectonic model which demonstrate residual velocity of NRC-net stations, less than 0.50 cm/year.

New global positioning system reference station in Brazil

GPS Solutions ◽  
2006 ◽  
Vol 11 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Jim Ray ◽  
David Crump ◽  
Miranda Chin
Keyword(s):  
Global Positioning System ◽  
Reference Station ◽  
Positioning System ◽  
Global Positioning

Aplikasi Pemosisi Lokal Berbasis Android Dengan Menggunakan GPS

INTI TALAFA ◽  
2018 ◽  
Vol 8 (2) ◽  
Author(s):  
Yaman Khaeruzzaman
Keyword(s):  
Global Positioning System ◽  
Positioning System ◽  
Database Server ◽  
Global Positioning

Seiring dengan pesatnya kemajuan teknologi saat ini, kebutuhan manusia menjadi lebih beragam, termasuk kebutuhan akan informasi. Tidak hanya media informasinya yang semakin beragam, jenis informasi yang dibutuhkan juga semakin beragam, salah satunya adalah kebutuhan informasi akan posisi kita terhadap lingkungan sekitar. Untuk memenuhi kebutuhan itu sebuah sistem pemosisi diciptakan. Sistem pemosisi yang banyak digunakan saat ini cenderung berfokus pada lingkup ruang yang besar (global) padahal, dalam lingkup ruang yang lebih kecil (lokal) sebuah sistem pemosisi juga diperlukan, seperti di ruang-ruang terbuka umum (taman atau kebun), ataupun dalam sebuah bangunan. Sistem pemosisi lokal yang ada saat ini sering kali membutuhkan infrastruktur yang mahal dalam pembangunannya. Aplikasi Pemosisi Lokal Berbasis Android dengan Menggunakan GPS ini adalah sebuah aplikasi yang dibangun untuk memenuhi kebutuhan pengguna akan informasi lokasi dan posisi mereka terhadap lingkungan di sekitarnya dalam lingkup ruang yang lebih kecil (lokal) dengan memanfaatkan perangkat GPS (Global Positioning System) yang telah tertanam dalam perangkat smartphone Android agar infrastruktur yang dibutuhkan lebih efisien. Dalam implementasinya, Aplikasi Pemosisi Lokal ini bertindak sebagai klien dengan dukungan sebuah Database Server yang berfungsi sebagai media penyimpanan data serta sumber referensi informasi yang dapat diakses melalui jaringan internet sehingga tercipta sebuah sistem yang terintegrasi secara global. Kata kunci: aplikasi, informasi, pemosisi, GPS.

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