Correction Method for the Observed Global Navigation Satellite System Ultra-Rapid Orbit Based on Dilution of Precision Values

For ultra-rapid orbits provided by the Global Navigation Satellite System (GNSS), the key parameters, accuracy and timeliness, must be taken into consideration in real-time and near real-time applications. However, insufficient observations in later epochs appear to generate low accuracy in observed orbits, for which a correlation between the Dilution of Precision (DOP) of the orbit parameters and their accuracy is found. To correct the observed GNSS ultra-rapid orbit, a correction method based on the DOP values is proposed by building the function models between DOP values and the orbit accuracy. With 10-day orbit determination experiments, the results show that the observed ultra-rapid-orbit errors, generated by insufficient observations, can be corrected by 12–22% for the last three hours of the observed orbits. Moreover, considering the timeliness constraints in ultra-rapid-orbit determination, a DOP amplification factor is defined to weight the contribution of each tracking station and optimize the station distribution in the orbit determination procedure. Finally, six schemes are designed to verify the method and strategy in determining the ultra-rapid orbit based on one-month observations. The orbit accuracy is found to decrease by 1.27–6.34 cm with increasing amplification factor from 5–20%. Thus, the observed ultra-orbit correction method proposed is ideal when considering accuracy and timeliness in ultra-rapid orbit determination.

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APLICAÇÃO DE GEOTECNOLOGIAS NA ANÁLISE DE VIABILIDADE TÉCNICA E ECONÔMICA DO PROJETO DE IMPLANTAÇÃO DO IFMA - CAMPUS ITAQUI-BACANGA.

Acta Tecnológica ◽

10.35818/acta.v14i2.949 ◽

2021 ◽

Vol 14 (2) ◽

pp. 105

Author(s):

Maelckson Bruno Barros Gomes ◽

André Luis Silva Santos

Keyword(s):

Real Time ◽

Global Navigation Satellite System ◽

Satellite System ◽

Navigation Satellite ◽

Real Time Kinematic ◽

Global Navigation ◽

Global Navigation Satellite

<p class="04CorpodoTexto">Este artigo tem por objetivo aplicar geotecnologias para obtenção de informações planialtimétricas a fim de avaliar a viabilidade de implantação do campus Centro Histórico/Itaqui-Bacanga do IFMA. Considerando que para realização de levantamento por métodos tradicionais é recomendado que seja realizado o destocamento e a limpeza do terreno previamente, avaliou-se a realização do levantamento planialtimétrico a partir de um par de receptores <em>Global Navigation Satellite System</em> (GNSS) pelo método <em>Real Time Kinematic</em> (RTK) pós processado e também a partir da realização de levantamento fotogramétrico, utilizando aeronave remotamente pilotada (ARP), popularmente conhecida como drone. Esta análise permitiu demonstrar que o aerolevantamento com a ARP pode ser aplicado na concepção inicial de um projeto de engenharia, conforme classificação do Tribunal de Contas da União (TCU) para níveis de precisão, pois obteve-se uma diferença orçamentária de 19% entre os projetos elaborados a partir das duas geotecnologias.</p><div> </div>

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LEO enhanced Global Navigation Satellite System (LeGNSS) for real-time precise positioning services

Advances in Space Research ◽

10.1016/j.asr.2018.08.017 ◽

2019 ◽

Vol 63 (1) ◽

pp. 73-93 ◽

Cited By ~ 14

Author(s):

Bofeng Li ◽

Haibo Ge ◽

Maorong Ge ◽

Liangwei Nie ◽

Yunzhong Shen ◽

...

Keyword(s):

Real Time ◽

Global Navigation Satellite System ◽

Satellite System ◽

Navigation Satellite ◽

Precise Positioning ◽

Global Navigation ◽

Global Navigation Satellite

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Use of Global Navigation Satellite System (GNSS) Software Defined Receiver (SDR) for Determining the 3D Real Time Position Variation in Dense Urban Areas by Averaging Method

2019 Sixth International Conference on Aerospace Science and Engineering (ICASE) ◽

10.1109/icase48783.2019.9059244 ◽

2019 ◽

Author(s):

Rizwan Ashfaq ◽

Muhammad Saleem

Keyword(s):

Real Time ◽

Global Navigation Satellite System ◽

Urban Areas ◽

Averaging Method ◽

Satellite System ◽

Navigation Satellite ◽

Time Position ◽

Global Navigation ◽

Global Navigation Satellite

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Distributed Orbit Determination for Global Navigation Satellite System with Inter-Satellite Link

Sensors ◽

10.3390/s19051031 ◽

2019 ◽

Vol 19 (5) ◽

pp. 1031 ◽

Cited By ~ 2

Author(s):

Yuanlan Wen ◽

Jun Zhu ◽

Youxing Gong ◽

Qian Wang ◽

Xiufeng He

Keyword(s):

Kalman Filter ◽

Extended Kalman Filter ◽

Global Navigation Satellite System ◽

Orbit Determination ◽

Measurement Data ◽

Satellite System ◽

Navigation Satellite ◽

Satellite Link ◽

Global Navigation ◽

Global Navigation Satellite

To keep the global navigation satellite system functional during extreme conditions, it is a trend to employ autonomous navigation technology with inter-satellite link. As in the newly built BeiDou system (BDS-3) equipped with Ka-band inter-satellite links, every individual satellite has the ability of communicating and measuring distances among each other. The system also has less dependence on the ground stations and improved navigation performance. Because of the huge amount of measurement data, the centralized data processing algorithm for orbit determination is suggested to be replaced by a distributed one in which each satellite in the constellation is required to finish a partial computation task. In the present paper, the balanced extended Kalman filter algorithm for distributed orbit determination is proposed and compared with the whole-constellation centralized extended Kalman filter, the iterative cascade extended Kalman filter, and the increasing measurement covariance extended Kalman filter. The proposed method demands a lower computation power; however, it yields results with a relatively good accuracy.

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Lower Bounds on DOP

Journal of Navigation ◽

10.1017/s0373463317000248 ◽

2017 ◽

Vol 70 (5) ◽

pp. 1041-1061 ◽

Cited By ~ 3

Author(s):

Peter F. Swaszek ◽

Richard J. Hartnett ◽

Kelly C. Seals

Keyword(s):

Lower Bounds ◽

Global Navigation Satellite System ◽

Satellite System ◽

Navigation Satellite ◽

Satellite Constellations ◽

Dilution Of Precision ◽

Gnss Positioning ◽

Satellite Selection ◽

Global Navigation ◽

Global Navigation Satellite

Code phase Global Navigation Satellite System (GNSS) positioning performance is often described by the Geometric or Position Dilution of Precision (GDOP or PDOP), functions of the number of satellites employed in the solution and their geometry. This paper develops lower bounds to both metrics solely as functions of the number of satellites, effectively removing the added complexity caused by their locations in the sky, to allow users to assess how well their receivers are performing with respect to the best possible performance. Such bounds will be useful as receivers sub-select from the plethora of satellites available with multiple GNSS constellations. The bounds are initially developed for one constellation assuming that the satellites are at or above the horizon. Satellite constellations that essentially achieve the bounds are discussed, again with value toward the problem of satellite selection. The bounds are then extended to a non-zero mask angle and to multiple constellations.

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Testing of Software for the Planning of a Linear Object GNSS Measurement Campaign under Simulated Conditions

Energies ◽

10.3390/en14237896 ◽

2021 ◽

Vol 14 (23) ◽

pp. 7896

Author(s):

Sławomir Figiel ◽

Cezary Specht ◽

Marek Moszyński ◽

Andrzej Stateczny ◽

Mariusz Specht

Keyword(s):

Global Navigation Satellite System ◽

Satellite System ◽

Navigation Satellite ◽

Dilution Of Precision ◽

Measurement Campaign ◽

Average Value ◽

Linear Object ◽

Global Navigation ◽

On The Road ◽

Global Navigation Satellite

The precision of a linear object measurement using satellite techniques is determined by the number and the relative position of the visible satellites by the receiver. The status of the visible constellation is described by the Dilution Of Precision (DOP). The obtained geometric coefficient values are dependent on many variables. When determining these values, field obstacles at the receiver location and satellite positions changing with time must be taken into account. Carrying out a series of surveys as part of a linear object Global Navigation Satellite System (GNSS) measurement campaign requires the optimisation problem to be solved. The manner of the inspection vehicle’s movement should be determined in such a way that the surveys are taken only within the pre-defined time frames and that the geometric coefficient values obtained at subsequent points of the route are as low as possible. The purpose of this article is to develop a software for the planning of a linear object GNSS measurement campaign to implemented in motion and taking into account the terrain model and its coverage. Additionally, it was determined how much the developed program improves DOP values on the planned route under simulated conditions. This software has no equivalent elsewhere in the world, as the current solutions for the planning of a GNSS measurement campaign, e.g., Trimble GNSS Planning, GNSS Mission Planning, or GPS Navigation Toolbox, allow the satellite constellation geometry to be analysed exclusively for specific coordinates and at a specific time. Analysis of the obtained simulation test results indicates that the campaign implementation in accordance with the pre-determined schedule significantly improves the quality of the recorded GNSS data. This is particularly noticeable when determining the position using the Global Positioning System (GPS) and GLObal NAvigation Satellite System (GLONASS) satellite constellations at the same time. During the tests conducted on the road along a three-kilometre-long route (tram loop) in Gdańsk Brzeźno, the average value of the obtained Position Dilution Of Precision (PDOP) decreased by 22.17% thanks to using the software to plan a linear object GNSS measurement campaign. The largest drop in the geometric coefficient values was noted for an area characterised by a very large number of field obstacles (trees with crowns and high buildings). Under these conditions, the PDOP value decreased by approx. 25%. In areas characterised by a small number of field obstacles (single trees in the vicinity of the track, clusters of trees and buildings located along the track), the changes in the PDOP were slightly smaller and amounted to several percent.

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Status of Satellite Orbit Determination and Time Synchronization Technology for Global Navigation Satellite System

Chinese Astronomy and Astrophysics ◽

10.1016/j.chinastron.2020.04.007 ◽

2020 ◽

Vol 44 (1) ◽

pp. 105-118

Author(s):

ZHOU Shan-shi ◽

HU Xiao-gong ◽

LIU Li ◽

HE Feng ◽

TANG Cheng-pan ◽

...

Keyword(s):

Global Navigation Satellite System ◽

Orbit Determination ◽

Time Synchronization ◽

Satellite Orbit ◽

Satellite System ◽

Navigation Satellite ◽

Global Navigation ◽

Global Navigation Satellite

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

Sensors ◽

10.3390/s18124130 ◽

2018 ◽

Vol 18 (12) ◽

pp. 4130 ◽

Cited By ~ 4

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.

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