Mitigation of ionospheric scintillation effects on GNSS precise point positioning (PPP) at low latitudes

Because of the special design of BeiDou navigation satellite system (BDS) constellation, the effects of ionospheric scintillation on operational BDS generally are more serious than on the global positioning system (GPS). As BDS is currently providing global services, it is increasingly important to seek strategies to mitigate the scintillation effects on BDS navigation and positioning services. In this study, an improved cycle-slip threshold model is proposed to decrease the high false-alarm rate of cycle-slips under scintillation conditions, thus avoiding the frequent unnecessary ambiguity resets in BDS precise point positioning (PPP) solution. We use one-year (from 23 March 2015 to 23 March 2016) BDS dataset from Hong Kong Sha Tin (HKST) station (22.4°N, 114.2°E; geomagnetic latitude: 15.4°N) to model the cycle-slip threshold and try to make it suitable for three types of BDS satellites and multiple scintillation levels. The availability of our mitigation strategy is validated by using three months (from 1 September 2015 to 30 November 2015) BDS dataset collected at 10 global navigation satellite system (GNSS) stations in Hong Kong. Positioning results demonstrate that our mitigated BDS PPP can prevent the sudden fluctuations of positioning errors induced by the ionospheric scintillation. Statistical results of BDS PPP experiments show that the mitigated solution can maintain an accuracy of about 0.08 m and 0.10 m in the horizontal and vertical components, respectively. Compared with standard BDS PPP, the accuracy of mitigated PPP can be improved by approximately 24.1%, 38.2%, and 47.9% in the east, north, and up directions, respectively. Our study demonstrates that considering different scintillation levels to establish appropriate cycle-slip threshold model in PPP processing can efficiently mitigate the ionospheric scintillation effects on BDS PPP.

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Improved precise point positioning in the presence of ionospheric scintillation

GPS Solutions ◽

10.1007/s10291-012-0309-1 ◽

2013 ◽

Vol 18 (1) ◽

pp. 51-60 ◽

Cited By ~ 23

Author(s):

Xiaohong Zhang ◽

Fei Guo ◽

Peiyuan Zhou

Keyword(s):

Precise Point Positioning ◽

Ionospheric Scintillation ◽

Point Positioning

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A Novel Approach to Improve GNSS Precise Point Positioning During Strong Ionospheric Scintillation: Theory and Demonstration

IEEE Transactions on Vehicular Technology ◽

10.1109/tvt.2019.2903988 ◽

2019 ◽

Vol 68 (5) ◽

pp. 4391-4403 ◽

Cited By ~ 9

Author(s):

Bruno Cesar Vani ◽

Biagio Forte ◽

Joao Francisco Galera Monico ◽

Susan Skone ◽

Milton Hirokazu Shimabukuro ◽

...

Keyword(s):

Precise Point Positioning ◽

Ionospheric Scintillation ◽

Novel Approach ◽

Point Positioning

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Accuracy assessment of Precise Point Positioning with multi-constellation GNSS data under ionospheric scintillation effects

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2017043 ◽

2018 ◽

Vol 8 ◽

pp. A15 ◽

Cited By ~ 20

Author(s):

Haroldo Antonio Marques ◽

Heloísa Alves Silva Marques ◽

Marcio Aquino ◽

Sreeja Vadakke Veettil ◽

João Francisco Galera Monico

Keyword(s):

Precise Point Positioning ◽

Accuracy Assessment ◽

Ionospheric Scintillation ◽

Small Scale ◽

Limiting Factor ◽

Atmospheric Effects ◽

Cycle Slips ◽

Satellite Geometry ◽

Point Positioning ◽

Gnss Data

GPS and GLONASS are currently the Global Navigation Satellite Systems (GNSS) with full operational capacity. The integration of GPS, GLONASS and future GNSS constellations can provide better accuracy and more reliability in geodetic positioning, in particular for kinematic Precise Point Positioning (PPP), where the satellite geometry is considered a limiting factor to achieve centimeter accuracy. The satellite geometry can change suddenly in kinematic positioning in urban areas or under conditions of strong atmospheric effects such as for instance ionospheric scintillation that may degrade satellite signal quality, causing cycle slips and even loss of lock. Scintillation is caused by small scale irregularities in the ionosphere and is characterized by rapid changes in amplitude and phase of the signal, which are more severe in equatorial and high latitudes geomagnetic regions. In this work, geodetic positioning through the PPP method was evaluated with integrated GPS and GLONASS data collected in the equatorial region under varied scintillation conditions. The GNSS data were processed in kinematic PPP mode and the analyses show accuracy improvements of up to 60% under conditions of strong scintillation when using multi-constellation data instead of GPS data alone. The concepts and analyses related to the ionospheric scintillation effects, the mathematical model involved in PPP with GPS and GLONASS data integration as well as accuracy assessment with data collected under ionospheric scintillation effects are presented.

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Mitigating high latitude ionospheric scintillation effects on GNSS Precise Point Positioning exploiting 1-s scintillation indices

Journal of Geodesy ◽

10.1007/s00190-021-01475-y ◽

2021 ◽

Vol 95 (3) ◽

Author(s):

Kai Guo ◽

Sreeja Vadakke Veettil ◽

Brian Jerald Weaver ◽

Marcio Aquino

Keyword(s):

High Latitude ◽

Precise Point Positioning ◽

Tracking Error ◽

Error Variance ◽

Satellite System ◽

The Arctic ◽

Ionospheric Scintillation ◽

Positioning Errors ◽

Point Positioning ◽

Scintillation Indices

AbstractIonospheric scintillation refers to rapid and random fluctuations in radio frequency signal intensity and phase, which occurs more frequently and severely at high latitudes under strong solar and geomagnetic activity. As one of the most challenging error sources affecting Global Navigation Satellite System (GNSS), scintillation can significantly degrade the performance of GNSS receivers, thereby leading to increased positioning errors. This study analyzes Global Positioning System (GPS) scintillation data recorded by two ionospheric scintillation monitoring receivers operational, respectively, in the Arctic and northern Canada during a geomagnetic storm in 2019. A novel approach is proposed to calculate 1-s scintillation indices. The 1-s receiver tracking error variances are then estimated, which are further used to mitigate the high latitude scintillation effects on GPS Precise Point Positioning. Results show that the 1-s scintillation indices can describe the signal fluctuations under scintillation more accurately. With the mitigation approach, the 3D positioning error is greatly reduced under scintillation analyzed in this study. Additionally, the 1-s tracking error variance achieves a better performance in scintillation mitigation compared with the previous approach which exploits 1-min tracking error variance estimated by the commonly used 1-min scintillation indices. This work is relevant for a better understanding of the high latitude scintillation effects on GNSS and is also beneficial for developing scintillation mitigation tools for GNSS positioning.

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