Preliminary testing of a method for local correction of monthly average ionospheric model for current situation: basing on data from single-frequency GNSS receivers

AbstractThe investigations on low-cost single frequency GNSS receivers at the Institute of Engineering Geodesy (IIGS) show that u-blox GNSS receivers combined with low-cost antennas and self-constructed L1-optimized choke rings can reach an accuracy which almost meets the requirements of geodetic applications (see Zhang and Schwieger [25]). However, the quality (accuracy and reliability) of low-cost GNSS receiver data should still be improved, particularly in environments with obstructions. The multipath effects are a major error source for the short baselines. The ground plate or the choke ring ground plane can reduce the multipath signals from the horizontal reflector (e. g. ground). However, the shieldings cannot reduce the multipath signals from the vertical reflectors (e. g. walls).Because multipath effects are spatially and temporally correlated, an algorithm is developed for reducing the multipath effect by considering the spatial correlations of the adjoined stations (see Zhang and Schwieger [24]). In this paper, an algorithm based on the temporal correlations will be introduced. The developed algorithm is based on the periodic behavior of the estimated coordinates and not on carrier phase raw data, which is easy to use. Because, for the users, coordinates are more accessible than the raw data. The multipath effect can cause periodic oscillations but the periods change over time. Besides this, the multipath effect’s influence on the coordinates is a mixture of different multipath signals from different satellites and different reflectors. These two properties will be used to reduce the multipath effect. The algorithm runs in two steps and iteratively. Test measurements were carried out in a multipath intensive environment; the accuracies of the measurements are improved by about 50 % and the results can be delivered in near-real-time (in ca. 30 minutes), therefore the algorithm is suitable for structural health monitoring applications.

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Broadcast ionospheric delay correction algorithm using reduced order adjusted spherical harmonics function for single-frequency GNSS receivers

Acta Geophysica ◽

10.1007/s11600-020-00515-z ◽

2021 ◽

Author(s):

M. S. R. Abhigna ◽

M. Sridhar ◽

P. Babu Sree Harsha ◽

K. Siva Krishna ◽

D. Venkata Ratnam

Keyword(s):

Spherical Harmonics ◽

Ionospheric Delay ◽

Single Frequency ◽

Correction Algorithm ◽

Reduced Order ◽

Gnss Receivers ◽

Delay Correction

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A New Ionospheric Model for Single Frequency GNSS User Applications Using Klobuchar Model Driven by Auto Regressive Moving Average (SAKARMA) Method Over Indian Region

IEEE Access ◽

10.1109/access.2020.2981365 ◽

2020 ◽

Vol 8 ◽

pp. 54535-54553 ◽

Cited By ~ 2

Author(s):

I. Lakshmi Mallika ◽

D. Venkata Ratnam ◽

Saravana Raman ◽

Gampala Sivavaraprasad

Keyword(s):

Moving Average ◽

Indian Region ◽

Single Frequency ◽

Ionospheric Model ◽

Model Driven ◽

Klobuchar Model ◽

Auto Regressive

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The use of low-cost, single-frequency GNSS receivers in mapping surveys

Survey Review ◽

10.1080/00396265.2016.1222344 ◽

2016 ◽

Vol 50 (358) ◽

pp. 46-56 ◽

Cited By ~ 7

Author(s):

M. Tsakiri ◽

A. Sioulis ◽

G. Piniotis

Keyword(s):

Low Cost ◽

Single Frequency ◽

Gnss Receivers

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Performance of Selected Ionospheric Models in Multi-Global Navigation Satellite System Single-Frequency Positioning over China

Remote Sensing ◽

10.3390/rs11172070 ◽

2019 ◽

Vol 11 (17) ◽

pp. 2070 ◽

Cited By ~ 7

Author(s):

Wang ◽

Chen ◽

Zhang ◽

Meng ◽

Wang

Keyword(s):

Global Navigation Satellite System ◽

Satellite System ◽

Ionospheric Delay ◽

Single Frequency ◽

Navigation Satellite ◽

Ionospheric Model ◽

Positioning Accuracy ◽

Grid Model ◽

Ionospheric Models ◽

Global Navigation Satellite

Ionospheric delay as the major error source needs to be properly handled in multi-GNSS (Global Navigation Satellite System) single-frequency positioning and the different ionospheric models exhibit apparent performance difference. In this study, two single-frequency positioning solutions with different ionospheric corrections are utilized to comprehensively analyze the ionospheric delay effects on multi-frequency and multi-constellation positioning performance, including standard point positioning (SPP) and ionosphere-constrained precise point positioning (PPP). The four ionospheric models studied are the GPS broadcast ionospheric model (GPS-Klo), the BDS (BeiDou Navigation Satellite System) broadcast ionospheric model (BDS-Klo), the BDS ionospheric grid model (BDS-Grid) and the Global Ionosphere Maps (GIM) model. Datasets are collected from 10 stations over one month in 2019. The solar remained calm and the ionosphere was stable during the test period. The experimental results show that for single-frequency SPP, the GIM model achieves the best accuracy, and the positioning accuracy of the BDS-Klo and BDS-Grid model is much better than the solution with GPS-Klo model in the N and U components. For the single-frequency PPP performance, the average convergence time of the ionosphere-constrained PPP is much reduced compared with the traditional PPP approach, where the improvements are of 11.2%, 11.9%, 21.3% and 39.6% in the GPS-Klo-, BDS-Klo-, BDS-Grid- and GIM-constrained GPS + GLONASS + BDS single-frequency PPP solutions, respectively. Furthermore, the positioning accuracy of the BDS-Grid- and GIM-constrained PPP is generally the same as the ionosphere-free combined single-frequency PPP. Through the combination of GPS, GLONASS and BDS, the positioning accuracy and convergence performance for all single-system single-frequency SPP/PPP solutions can be effectively improved.

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Attitude Determination using Single Frequency GNSS Receivers for Small UAVs

The Abstracts of the international conference on advanced mechatronics toward evolutionary fusion of IT and mechatronics ICAM ◽

10.1299/jsmeicam.2015.6.112 ◽

2015 ◽

Vol 2015.6 (0) ◽

pp. 112 ◽

Cited By ~ 2

Author(s):

Taro Suzuki ◽

Takeshi Akehi ◽

Takuma Massubuchi ◽

Yoshiharu Amano

Keyword(s):

Attitude Determination ◽

Single Frequency ◽

Gnss Receivers

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Potential of Cost-Efficient Single Frequency GNSS Receivers for Water Vapor Monitoring

Remote Sensing ◽

10.3390/rs10091493 ◽

2018 ◽

Vol 10 (9) ◽

pp. 1493 ◽

Cited By ~ 10

Author(s):

Andreas Krietemeyer ◽

Marie-claire ten Veldhuis ◽

Hans van der Marel ◽

Eugenio Realini ◽

Nick van de Giesen

Keyword(s):

Water Vapor ◽

Low Cost ◽

Global Navigation Satellite Systems ◽

Single Frequency ◽

Small Scale ◽

Reference Network ◽

Tropospheric Delay ◽

Dual Frequency ◽

Gnss Receivers ◽

Cost Efficient

Dual-frequency Global Navigation Satellite Systems (GNSSs) enable the estimation of Zenith Tropospheric Delay (ZTD) which can be converted to Precipitable Water Vapor (PWV). The density of existing GNSS monitoring networks is insufficient to capture small-scale water vapor variations that are especially important for extreme weather forecasting. A densification with geodetic-grade dual-frequency receivers is not economically feasible. Cost-efficient single-frequency receivers offer a possible alternative. This paper studies the feasibility of using low-cost receivers to increase the density of GNSS networks for retrieval of PWV. We processed one year of GNSS data from an IGS station and two co-located single-frequency stations. Additionally, in another experiment, the Radio Frequency (RF) signal from a geodetic-grade dual-frequency antenna was split to a geodetic receiver and two low-cost receivers. To process the single-frequency observations in Precise Point Positioning (PPP) mode, we apply the Satellite-specific Epoch-differenced Ionospheric Delay (SEID) model using two different reference network configurations of 50–80 km and 200–300 km mean station distances, respectively. Our research setup can distinguish between the antenna, ionospheric interpolation, and software-related impacts on the quality of PWV retrievals. The study shows that single-frequency GNSS receivers can achieve a quality similar to that of geodetic receivers in terms of RMSE for ZTD estimations. We demonstrate that modeling of the ionosphere and the antenna type are the main sources influencing the ZTD precision.

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A Refinement Method of Real-Time Ionospheric Model for China

Remote Sensing ◽

10.3390/rs12203354 ◽

2020 ◽

Vol 12 (20) ◽

pp. 3354

Author(s):

Yang Wang ◽

Yibin Yao ◽

Liang Zhang ◽

Mingshan Fang

Keyword(s):

Real Time ◽

Total Electron Content ◽

Global Navigation Satellite Systems ◽

Single Frequency ◽

Electron Content ◽

Vertical Total Electron Content ◽

Ionospheric Model ◽

Total Electron ◽

Satellite Systems ◽

Refinement Method

Ionospheric delay is a crucial error source and determines the source of single-frequency precise point positioning (SF-PPP) accuracy. To meet the demands of real-time SF-PPP (RT-SF-PPP), several international global navigation satellite systems (GNSS) service (IGS) analysis centers provide real-time global ionospheric vertical total electron content (VTEC) products. However, the accuracy distribution of VTEC products is nonuniform. Proposing a refinement method is a convenient means to obtain a more accuracy and consistent VTEC product. In this study, we proposed a refinement method of a real-time ionospheric VTEC model for China and carried out experiments to validate the model effectiveness. First, based on the refinement method and the Centre National d’Études Spatiales (CNES) VTEC products, three refined real-time global ionospheric models (RRTGIMs) with one, three, and six stations in China were built via GNSS observations. Second, the slant total electron content (STEC) and Jason-3 VTEC were used as references to evaluate VTEC accuracy. Third, RT-SF-PPP was used to evaluate the accuracy in the positioning domain. Results showed that even if using only one station to refine the global ionospheric model, the refined model achieved a better performance than CNES and the Center for Orbit Determination in Europe (CODE). The refinement model with six stations was found to be the best of the three refinement models.

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