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Advances in GNSS Positioning and GNSS Remote Sensing

A special issue of Sensors (ISSN 1424-8220). This special issue belongs to the section "Remote Sensors".

Deadline for manuscript submissions: closed (31 August 2023) | Viewed by 35896

Special Issue Editors


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Guest Editor
Institute of Solar Terrestrial Physics of Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk, Novosibirsk Oblast, Russia
Interests: ionosphere; total electron content; global electron content; travelling ionosphere disturbances; GNSS; space weather
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Guest Editor
Department of Electronics and Communication Engineering, Koneru Lakshmaiah University, Vaddeswaram, Andhra Pradesh 522502, India
Interests: electrical and communication engineering

Special Issue Information

Dear Colleagues,

Scientists and engineers use data from global navigation satellite systems (GNSS) for different tasks: autonomous navigation, transport monitoring, construction, GNSS reflectometry, GNSS ionosphere monitoring, etc. To improve GNSS precision, many devices combine different sensors and GNSS receivers, scientists find ways to make GNSS receivers (and satellites) better, and mathematicians improves navigation solutions. Combining different navigation systems (GPS, GLONASS, Galileo, BeiDou) also helped achieve precise positioning and remote sensing. However, applied tasks require more and more from science in this field.

This Special Issue considers varied solutions and applications to improve GNSS navigation quality, as well as new applications and improvements in GNSS remote sensing. Special attention is devoted to smartphones and low-cost receivers, intellectual data analysis for GNSS, and combining different sensors with GNSS. We consider different types of navigation including single-frequency, dual-frequency, multi-frequency, Real-Time Kinematic (RTK), and Precise Point Positioning navigation. 

Dr. Yury Yasyukevich
Prof. Dr. Baocheng Zhang
Prof. Dr. Venkat Ratnam
Guest Editors

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Published Papers (11 papers)

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Editorial

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6 pages, 527 KiB  
Editorial
Advances in GNSS Positioning and GNSS Remote Sensing
by Yury V. Yasyukevich, Baocheng Zhang and Venkata Ratnam Devanaboyina
Sensors 2024, 24(4), 1200; https://doi.org/10.3390/s24041200 - 12 Feb 2024
Cited by 4 | Viewed by 4018
Abstract
Scientists and engineers use data utilize global navigation satellite systems (GNSSs) for a multitude of tasks: autonomous navigation, transport monitoring, construction, GNSS reflectometry, GNSS ionosphere monitoring, etc [...] Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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Research

Jump to: Editorial

11 pages, 16517 KiB  
Communication
The Spectrum of Global Electron Content: A New Potential Indicator of Space Weather Activity
by Josep Maria Aroca-Farrerons, Manuel Hernández-Pajares, Haixia Lyu, David Roma-Dollase, Raul Orus-Perez, Alberto García-Rigo, Victoria Graffigna, Germán Olivares-Pulido, Enric Monte-Moreno, Heng Yang and Qi Liu
Sensors 2024, 24(2), 393; https://doi.org/10.3390/s24020393 - 9 Jan 2024
Cited by 1 | Viewed by 1180
Abstract
The time evolution of the total number of free electrons in the Earth’s ionosphere, i.e., the Global Electron Content (GEC), during more than two solar cycles is analyzed in this work. The GEC time series has been extracted from the Global Ionospheric Maps [...] Read more.
The time evolution of the total number of free electrons in the Earth’s ionosphere, i.e., the Global Electron Content (GEC), during more than two solar cycles is analyzed in this work. The GEC time series has been extracted from the Global Ionospheric Maps (GIMs) of Vertical Total Electron Content (VTEC) estimated by UPC-IonSAT with TOMION-v1 software from global GPS measurements since the end of 1996. A dual-layer voxel-based tomographic model solved with a forward Kalman scalar filter, from dual-frequency carrier GPS data only, provides the so-called UQRG GIM after VTEC kriging interpolation, with a resolution of 15 min in time, 5° in longitude and 2.5° in latitude. UQRG is one of the best behaving GIMs in the International GNSS Service (IGS).In this context, the potential application of the GEC spectrum evolution as a potential space weather index is discussed and demonstrated. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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13 pages, 5834 KiB  
Article
Ionospheric Weather at Two Starlink Launches during Two-Phase Geomagnetic Storms
by Tamara Gulyaeva, Manuel Hernández-Pajares and Iwona Stanislawska
Sensors 2023, 23(15), 7005; https://doi.org/10.3390/s23157005 - 7 Aug 2023
Cited by 4 | Viewed by 2350
Abstract
The launch of a series of Starlink internet satellites on 3 February 2022 (S-36), and 7 July 2022 (S-49), coincided with the development of two-phase geomagnetic storms. The first launch S-36 took place in the middle of the moderate two-phase space weather storm, [...] Read more.
The launch of a series of Starlink internet satellites on 3 February 2022 (S-36), and 7 July 2022 (S-49), coincided with the development of two-phase geomagnetic storms. The first launch S-36 took place in the middle of the moderate two-phase space weather storm, which induced significant technological consequences. After liftoff on 3 February at 18:13 UT, all Starlink satellites reached an initial altitude of 350 km in perigee and had to reach an altitude of ~550 km after the maneuver. However, 38 of 49 launched spacecrafts did not reach the planned altitude, left orbit due to increased drag and reentered the atmosphere on 8 February. A geomagnetic storm on 3–4 February 2022 has increased the density of the neutral atmosphere up to 50%, increasing drag of the satellites and dooming most of them. The second launch of S-49 at 13:11 UT on 7 July 2022 was successful at the peak of the two-phase geomagnetic storm. The global ionospheric maps of the total electron content (GIM-TEC) have been used to produce the ionospheric weather GIM-W index maps and Global Electron Content (GEC). We observed a GEC increment from 10 to 24% for the storm peak after the Starlink launch at both storms, accompanying the neutral density increase identified earlier. GIM-TEC maps are available with a lag (delay) of 1–2 days (real-time GIMs have a lag less than 15 min), so the GIMs forecast is required by the time of the launch. Comparisons of different GIMs forecast techniques are provided including the Center for Orbit Determination in Europe (CODE), Beijing (BADG and CASG) and IZMIRAN (JPRG) 1- and 2-day forecasts, and the Universitat Politecnica de Catalunya (UPC-ionSAT) forecast for 6, 12, 18, 24 and 48 h in advance. We present the results of the analysis of evolution of the ionospheric parameters during both events. The poor correspondence between observed and predicted GIM-TEC and GEC confirms an urgent need for the industry–science awareness of now-casting/forecasting/accessibility of GIM-TECs during the space weather events. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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23 pages, 7592 KiB  
Article
Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC Ionospheric Models: A Comparison in Total Electron Content and Positioning Domains
by Yury V. Yasyukevich, Dmitry Zatolokin, Artem Padokhin, Ningbo Wang, Bruno Nava, Zishen Li, Yunbin Yuan, Anna Yasyukevich, Chuanfu Chen and Artem Vesnin
Sensors 2023, 23(10), 4773; https://doi.org/10.3390/s23104773 - 15 May 2023
Cited by 8 | Viewed by 2292
Abstract
Global navigation satellite systems (GNSS) provide a great data source about the ionosphere state. These data can be used for testing ionosphere models. We studied the performance of nine ionospheric models (Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC) both in [...] Read more.
Global navigation satellite systems (GNSS) provide a great data source about the ionosphere state. These data can be used for testing ionosphere models. We studied the performance of nine ionospheric models (Klobuchar, NeQuickG, BDGIM, GLONASS, IRI-2016, IRI-2012, IRI-Plas, NeQuick2, and GEMTEC) both in the total electron content (TEC) domain—i.e., how precise the models calculate TEC—and in the positioning error domain—i.e., how the models improve single frequency positioning. The whole data set covers 20 years (2000–2020) from 13 GNSS stations, but the main analysis involves data during 2014–2020 when calculations are available from all the models. We used single-frequency positioning without ionospheric correction and with correction via global ionospheric maps (IGSG) data as expected limits for errors. Improvements against noncorrected solution were as follows: GIM IGSG—22.0%, BDGIM—15.3%, NeQuick2—13.8%, GEMTEC, NeQuickG and IRI-2016—13.3%, Klobuchar—13.2%, IRI-2012—11.6%, IRI-Plas—8.0%, GLONASS—7.3%. TEC bias and mean absolute TEC errors for the models are as follows: GEMTEC—−0.3 and 2.4 TECU, BDGIM—−0.7 and 2.9 TECU, NeQuick2—−1.2 and 3.5 TECU, IRI-2012—−1.5 and 3.2 TECU, NeQuickG—−1.5 and 3.5 TECU, IRI-2016—−1.8 and 3.2 TECU, Klobuchar—1.2 and 4.9 TECU, GLONASS—−1.9 and 4.8 TECU, and IRI-Plas—3.1 and 4.2 TECU. While TEC and positioning domains differ, new-generation operational models (BDGIM and NeQuickG) could overperform or at least be at the same level as classical empirical models. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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19 pages, 7913 KiB  
Article
Low-Cost Dual-Frequency GNSS Receivers and Antennas for Surveying in Urban Areas
by Veton Hamza, Bojan Stopar, Oskar Sterle and Polona Pavlovčič-Prešeren
Sensors 2023, 23(5), 2861; https://doi.org/10.3390/s23052861 - 6 Mar 2023
Cited by 13 | Viewed by 4485
Abstract
Low-cost dual-frequency global navigation satellite system (GNSS) receivers have recently been tested in various positioning applications. Considering that these sensors can now provide high positioning accuracy at a lower cost, they can be considered an alternative to high-quality geodetic GNSS devices. The main [...] Read more.
Low-cost dual-frequency global navigation satellite system (GNSS) receivers have recently been tested in various positioning applications. Considering that these sensors can now provide high positioning accuracy at a lower cost, they can be considered an alternative to high-quality geodetic GNSS devices. The main objectives of this work were to analyze the differences between geodetic and low-cost calibrated antennas on the quality of observations from low-cost GNSS receivers and to evaluate the performance of low-cost GNSS devices in urban areas. In this study, a simple RTK2B V1 board u-blox ZED-F9P (Thalwil, Switzerland) was tested in combination with a low-cost calibrated and geodetic antenna in open-sky and adverse conditions in urban areas, while a high-quality geodetic GNSS device was used as a reference for comparison. The results of the observation quality check show that low-cost GNSS instruments have a lower carrier-to-noise ratio (C/N0) than geodetic instruments, especially in the urban areas where the difference is larger and in favor of the geodetic GNSS instruments. The root-mean-square error (RMSE) of the multipath error in the open sky is twice as high for low-cost as for geodetic instruments, while this difference is up to four times greater in urban areas. The use of a geodetic GNSS antenna does not show a significant improvement in the C/N0 and multipath of low-cost GNSS receivers. However, the ambiguity fix ratio is larger when geodetic antennas are used, with a difference of 1.5% and 18.4% for the open-sky and urban conditions, respectively. It should be noted that float solutions may become more evident when low-cost equipment is used, especially for short sessions and in urban areas with more multipath. In relative positioning mode, low-cost GNSS devices were able to provide horizontal accuracy lower than 10 mm in urban areas in 85% of sessions, while the vertical and spatial accuracy was lower than 15 mm in 82.5% and 77.5% of the sessions, respectively. In the open sky, low-cost GNSS receivers achieve a horizontal, vertical, and spatial accuracy of 5 mm for all sessions considered. In RTK mode, positioning accuracy varies between 10–30 mm in the open-sky and urban areas, while better performance is demonstrated for the former. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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15 pages, 1946 KiB  
Article
Preparations for Galileo PRS in Poland
by Krzysztof Bronk, Adam Lipka and Rafal Niski
Sensors 2023, 23(4), 1770; https://doi.org/10.3390/s23041770 - 4 Feb 2023
Cited by 1 | Viewed by 2272
Abstract
This article discusses the increasing security risk for the Global Navigation Satellite System (GNSS) due to both unintentional and deliberate interference (attacks), which have gotten significantly worse in 2022 due to tense the international situation. The upcoming Galileo Public Regulated Service (PRS), which [...] Read more.
This article discusses the increasing security risk for the Global Navigation Satellite System (GNSS) due to both unintentional and deliberate interference (attacks), which have gotten significantly worse in 2022 due to tense the international situation. The upcoming Galileo Public Regulated Service (PRS), which is more resilient and robust than initial GNSS open services, is one of the key solutions for that problem. The technical description of this service, aspects regarding its implementation in the EU and the role of designated governmental authorities in that process are extensively covered in the first sections of the article. The next relevant issue brought up in the paper is the PRS signals’ coexistence with amateur services operating within the same frequency resources, which have recently became a source of significant controversy in Europe. Finally, the article presents the Polish contribution to the Galileo PRS preparatory actions, covering the participation in two international R&D projects, the developed measurement station and initial results for the GNSS receiver’s jamming and spoofing resistance tests, as well as the concept of the Galileo PRS threats detection system. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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18 pages, 4859 KiB  
Article
A Novel Ionospheric Disturbance Index to Evaluate the Global Effect on BeiDou Navigation Satellite System Signal Caused by the Moderate Geomagnetic Storm on May 12, 2021
by Liming He, Cong Guo, Quanyou Yue, Shixuan Zhang, Zenghui Qin and Junfei Zhang
Sensors 2023, 23(3), 1183; https://doi.org/10.3390/s23031183 - 20 Jan 2023
Cited by 6 | Viewed by 2496
Abstract
In this paper, we propose a new method to quantitatively evaluate the quality of the carrier phase observation signals of the BeiDou Navigation Satellite System (BDS) during weak and moderate geomagnetic storms. We take a moderate geomagnetic storm that occurred on 12 May [...] Read more.
In this paper, we propose a new method to quantitatively evaluate the quality of the carrier phase observation signals of the BeiDou Navigation Satellite System (BDS) during weak and moderate geomagnetic storms. We take a moderate geomagnetic storm that occurred on 12 May 2021 during the 25th solar cycle as an example. The results show that the newly defined PAS (Percentage of Affected Satellites) index shows significant anomaly changes during the moderate geomagnetic storm. Its variation trend has good correlations with the geomagnetic storm Kp index and Dst index. The anomaly stations are mainly distributed in the equatorial region and auroral region in the northern and southern hemispheres. The proposed PAS index has a good indication for both BDS2 and BDS3 satellites. We further validated this index by calculating the Precise Point Position (PPP) positioning error. We found that the anomaly period of PAS has strong consistency with the abnormal period of PPP positioning accuracy. This study could provide methodological support for the evaluation of the signal quality and analysis of positioning accuracy for the BeiDou satellite navigation system under different space weather conditions. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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13 pages, 12942 KiB  
Article
Performance Evaluation of GNSS Position Augmentation Methods for Autonomous Vehicles in Urban Environments
by Harihara Bharathy Swaminathan, Aron Sommer, Andreas Becker and Martin Atzmueller
Sensors 2022, 22(21), 8419; https://doi.org/10.3390/s22218419 - 2 Nov 2022
Cited by 10 | Viewed by 3555
Abstract
Global Navigation Satellite Systems provide autonomous vehicles with precise position information through the process of position augmentation. This paper presents a series of performance tests aimed to compare the position accuracy of augmentation techniques such as classical Differential Global Navigation Satellite System, Real-time [...] Read more.
Global Navigation Satellite Systems provide autonomous vehicles with precise position information through the process of position augmentation. This paper presents a series of performance tests aimed to compare the position accuracy of augmentation techniques such as classical Differential Global Navigation Satellite System, Real-time Kinematic and Real-time eXtended. The aim is to understand the limitations and choose the best position augmentation technique in order to obtain accurate, trustworthy position estimates of a vehicle in urban environments. The tests are performed in and around the German cities of Wuppertal and Duesseldorf, using a vehicle fitted with the navigation system POS-LV 220, developed by Applanix Corporation. In order to evaluate the real-time performance of position augmentation techniques in a highly challenging environment, a total of four test regions are selected. The four test regions are characterized mainly by uneven terrain with tall buildings around the University of Wuppertal, flat terrain with roads of varying width in the city centre of Wuppertal and Duesseldorf and flat terrain in a tunnel section located in the city of Wuppertal. The performances of the different position augmentation are compared using a Root Mean Square (RMS) error estimate obtained as an output from the Applanix system. Furthermore, a High-Definition map of the environment is used for the purpose of model validation, which justifies the use of RMS error estimate as an evaluation metric for the performance analysis tests. According to the performance tests carried out as per the conditions specified in this paper, the Real-time eXtended (RTX) position augmentation method enables to obtain a more robust position information of the vehicle than Real-time Kinematic (RTK) method, with a typical accuracy of a few centimeter in an urban environment. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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13 pages, 4128 KiB  
Article
Fault-Free Protection Level Equation for CLAS PPP-RTK and Experimental Evaluations
by Euiho Kim, Jaeyoung Song, Yujin Shin, Saekyul Kim, Pyo-Woong Son, Sulgee Park and Sanghyun Park
Sensors 2022, 22(9), 3570; https://doi.org/10.3390/s22093570 - 7 May 2022
Cited by 3 | Viewed by 2681
Abstract
Centimeter level augmentation system (CLAS) of the quasi-zenith satellite system (QZSS) is the first precise point positioning-real time kinematic (PPP-RTK) augmentation system of the global navigation satellite system (GNSS), which is currently providing services for Japan. CLAS broadcasts the state-space representation of correction [...] Read more.
Centimeter level augmentation system (CLAS) of the quasi-zenith satellite system (QZSS) is the first precise point positioning-real time kinematic (PPP-RTK) augmentation system of the global navigation satellite system (GNSS), which is currently providing services for Japan. CLAS broadcasts the state-space representation of correction messages along with integrity messages regarding satellite faults and the quality index of each correction. In other GNSS augmentation systems, such as the space-based augmentation system (SBAS) of GNSS, the quality indices of correction messages are used to generate fault-free protection levels that represent a position bound containing a true user position with a probability of missed detections. Although the protection level equations are well defined for the SBAS, a protection level equation for the CLAS PPP-RTK service has not been rigorously discussed in the literature. This paper proposes a fault-free protection level equation for the PPP-RTK methods that considers the probability of correct integer ambiguity fixes in the GNSS carrier phase measurements as well as the CLAS correction quality messages. The computed protection levels with position errors were experimentally compared by processing the GNSS measurements from the GNSS Earth Observation Network (GEONET) stations in Japan and the L6 messages from the CLAS broadcast using the virtual reference station-real time kinematic (VRS-RTK) techniques. Our results, based on the GEONET dataset spanning 7 days, showed that the computed protection levels using the proposed equations were larger than the position errors for all epochs. In the dataset, the RMS errors of the CLAS VRS-RTK position were 4.6 and 14 cm in the horizontal and vertical directions, respectively, whereas the horizontal protection levels ranged from 25 cm to 2.3 m and the vertical protection levels ranged from 50 cm to 5.2 m based on fault-free integrity risk of 107. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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17 pages, 2879 KiB  
Article
Combating Single-Frequency Jamming through a Multi-Frequency, Multi-Constellation Software Receiver: A Case Study for Maritime Navigation in the Gulf of Finland
by Saiful Islam, Mohammad Zahidul H. Bhuiyan, Sarang Thombre and Sanna Kaasalainen
Sensors 2022, 22(6), 2294; https://doi.org/10.3390/s22062294 - 16 Mar 2022
Cited by 11 | Viewed by 4628
Abstract
Today, a substantial portion of global trade is carried by sea. Consequently, the reliance on Global Navigation Satellite System (GNSS)-based navigation in the oceans and inland waterways has been rapidly growing. GNSS is vulnerable to various radio frequency interference. The objective of this [...] Read more.
Today, a substantial portion of global trade is carried by sea. Consequently, the reliance on Global Navigation Satellite System (GNSS)-based navigation in the oceans and inland waterways has been rapidly growing. GNSS is vulnerable to various radio frequency interference. The objective of this research is to propose a resilient Multi-Frequency, Multi-Constellation (MFMC) receiver in the context of maritime navigation to identify any GNSS signal jamming incident and switch to a jamming-free signal immediately. With that goal in mind, the authors implemented a jamming event detector that can identify the start, end, and total duration of the detected jamming event on any of the impacted GNSS signal(s). By utilizing a jamming event detector, the proposed resilient MFMC receiver indeed provides a seamless positioning solution in the event of single-frequency jamming on either the lower or upper L-band. In addition, this manuscript also contains positioning performance analysis of GPS-L5-only, Galileo-E5a-only, and Galileo-E5b-only signals and their multi-GNSS combinations in a maritime operational environment in the Gulf of Finland. The positioning performance of lower L-band GNSS signals in a maritime environment has not been thoroughly investigated as per the authors’ knowledge. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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20 pages, 5113 KiB  
Article
A Field Calibration Solution to Achieve High-Grade-Level Performance for Low-Cost Dual-Frequency GNSS Receiver and Antennas
by Andreas Krietemeyer, Hans van der Marel, Nick van de Giesen and Marie-Claire ten Veldhuis
Sensors 2022, 22(6), 2267; https://doi.org/10.3390/s22062267 - 15 Mar 2022
Cited by 10 | Viewed by 3415
Abstract
Low-cost dual-frequency receivers and antennas have created opportunities for a wide range of new applications, in regions and disciplines where traditional GNSS equipment is unaffordable. However, the major drawback of using low-cost antenna equipment is that antenna phase patterns are typically poorly defined. [...] Read more.
Low-cost dual-frequency receivers and antennas have created opportunities for a wide range of new applications, in regions and disciplines where traditional GNSS equipment is unaffordable. However, the major drawback of using low-cost antenna equipment is that antenna phase patterns are typically poorly defined. Therefore, the noise in tropospheric zenith delay and coordinate time series is increased and systematic errors may occur. Here, we present a field calibration method that fully relies on low-cost solutions. It does not require costly software, uses low-cost equipment (~500 Euros), requires limited specialist expertise, and takes complex processing steps into the cloud. The application is more than just a relative antenna calibration: it is also a means to assess the quality and performance of the antenna, whether this is at a calibration site or directly in the field. We cover PCV calibrations, important for deformation monitoring, GNSS meteorology and positioning, and the computation of PCOs when the absolute position is of interest. The method is made available as an online web service. The performance of the calibration method is presented for a range of antennas of different quality and price in combination with a low-cost dual-frequency receiver. Carrier phase residuals of the low-cost antennas are reduced by 11–34% on L1 and 19–39% on L2, depending on the antenna type and ground plane used. For the cheapest antenna, when using a circular ground plane, the L1 residual is reduced from 3.85 mm before to 3.41 mm after calibration, and for L2 from 5.34 mm to 4.3 mm. The calibration reduces the Median Absolute Deviations (MADs) of the low-cost antennas in the vertical direction using Post Processed Kinematic (PPK) by 20–24%. For the cheapest antenna, the MAD is reduced from 5.6 to 3.8 mm, comparable to a geodetic-grade antenna (3.5 mm MAD). The calibration also has a positive impact on the Precise Point Positioning (PPP) results, delivering more precise results and reducing height biases. Full article
(This article belongs to the Special Issue Advances in GNSS Positioning and GNSS Remote Sensing)
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