KLOBUCHAR AND NEQUICK G IONOSPHERIC MODELS COMPARISON FOR MULTI-GNSS SINGLE-FREQUENCY CODE POINT POSITIONING IN THE BRAZILIAN REGION

One of the main error sources in GNSS positioning comes from the ionosphere, an atmospheric layer that stays in the signal path between the satellite and the receiver. For single frequency positioning, the ionospheric effects can be minimized by using an ionospheric model e.g. Klobuchar or NeQuick G. These models are respectively associated to GPS and Galileo systems through their navigation messages, which broadcast coefficients that describe the worldwide ionospheric behavior, and the calculated ionospheric delay is then applied in the pseudorange observations. In this paper, it is presented a comparison between these two models in multi-GNSS (GPS and Galileo) single frequency point positioning, considering two Brazilian stations at different magnetic latitudes, and covered months of weak and strong ionospheric activity from 2013 to 2018. The results indicate a better performance of NeQuick G model compared to the Klobuchar. Considering all the analyzed periods and stations, Klobuchar improves the positioning accuracy in 16% and 50% in periods of weak and strong ionospheric activity, respectively, while NeQuick G improves the accuracy in 31% and 55%.

[1]  Ciro Gioia,et al.  Benefit of the NeQuick Galileo Version in GNSS Single-Point Positioning , 2013 .

[2]  A. J. Van Dierendonck,et al.  Measuring Ionospheric Scintillation Effects from GPS Signals , 2001 .

[3]  Sandro M. Radicella,et al.  The NeQuick model genesis, uses and evolution , 2009 .

[4]  Milton Hirokazu Shimabukuro,et al.  Visual exploration and analysis of ionospheric scintillation monitoring data: The ISMR Query Tool , 2017, Comput. Geosci..

[5]  J. Nurmi,et al.  PVT Computation Issues in Mixed Galileo/GPS Reception , 2015 .

[6]  Marcelo Tomio Matsuoka,et al.  Correcão ionosférica utilizando os MAPAS: Globais do TEC DO IGS: Avaliação no posicionamento por ponto na região brasileira , 2007 .

[7]  Yunbin Yuan,et al.  An examination of the Galileo NeQuick model: comparison with GPS and JASON TEC , 2017, GPS Solutions.

[8]  Bernhard Hofmann-Wellenhof,et al.  GNSS - Global Navigation Satellite Systems: GPS, GLONASS, Galileo, and more , 2007 .

[9]  R. Piriz,et al.  Performance of the NeQuick G iono model for single-frequency GNSS timing applications , 2016, 2016 European Frequency and Time Forum (EFTF).

[10]  O. Montenbruck,et al.  Introduction to GNSS , 2017 .

[11]  J. Klobuchar.  Ionospheric Time-Delay Algorithm for Single-Frequency GPS Users , 1987, IEEE Transactions on Aerospace and Electronic Systems.

[12]  S. Skone,et al.  Limitations in GPS receiver tracking performance under ionospheric scintillation conditions , 2001 .

[13]  Marcio Aquino,et al.  Accuracy assessment of Precise Point Positioning with multi-constellation GNSS data under ionospheric scintillation effects , 2018 .

[14]  H. J. Strangeways,et al.  WBMod assisted PLL GPS software receiver for mitigating scintillation affect in high latitude region , 2011, 2011 XXXth URSI General Assembly and Scientific Symposium.

[15]  Thomas Hobiger,et al.  Atmospheric signal propagation , 2017 .

[16]  Roberto Prieto-Cerdeira,et al.  Status of NeQuick G After the Solar Maximum of Cycle 24 , 2018 .

[17]  Patrick Fell,et al.  Satellite Geodesy—Foundations, Methods, and Applications , 1994 .

[18]  Marcelo Tomio Matsuoka,et al.  Desempenho do modelo global da ionosfera do IGS: avaliação no posicionamento por ponto na região sul do Brasil em período de alta atividade solar , 2009 .