The primary goal of the project is to develop and implement a robust, independent, realtime syste... more The primary goal of the project is to develop and implement a robust, independent, realtime system that will inform users and CORS operators of the quality, dependability, and fitnessfor-purpose of NRTK positioning results. The system, dubbed the Real-Time Quality Control (RTQC) system is unique in that the quality control computations are performed and reported in real-time and the quality control process integrates CORS and mobile data. Although options exist to perform quality control analysis in a post-processed mode, no such options are available in real-time nor are they independent of proprietary algorithms.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-b... more In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-based kinematic positioning in Australian urban environments are presented and analysed. As the standalone GNSS positioning is unable to deliver the accuracy required for absolute positioning in Intelligent Transport Systems (ITS), more advanced technologies are needed, and the Australian SBAS with PPP capabilities is a candidate. Kinematic tests were run in scenarios characterised by four environments: high-density urban, low-density urban, suburban and tree-canopy. SBAS positioning performance was evaluated in the different environments, with a focus on its capability to provide lane identification and thus aid ITS applications.
The FAIR principles of Wilkinson et al. [1] are finding their way from research into application ... more The FAIR principles of Wilkinson et al. [1] are finding their way from research into application domains, one of which is the precise positioning with global satellite navigation systems (GNSS). Current GNSS users demand that data and services are findable online, accessible via open protocols (by both, machines and humans), interoperable with their legacy systems and reusable in various settings. Comprehensive metadata are essential in seamless communication between GNSS data and service providers and their users, and, for decades, geodetic and geospatial standards are efficiently implemented to support this. However, GNSS user community is transforming from precise positioning by highly specialised use by geodetic professionals to every-day precise positioning by autonomous vehicles or wellness obsessed citizens. Moreover, rapid technological developments allow alternative ways of offering data and services to their users. These transforming circumstances warrant a review whether ...
Centimetre-level accurate ionospheric corrections are required for a high accuracy and rapid conv... more Centimetre-level accurate ionospheric corrections are required for a high accuracy and rapid convergence of Precise Point Positioning (PPP) GNSS positioning solutions. This research aims to evaluate the accuracy of a local/regional ionospheric delay model using a linear interpolation method across Australia. The accuracy of the ionospheric corrections is assessed as a function of both different latitudinal regions and the number and spatial density of GNSS Continuously Operating Reference Stations (CORSs). Our research shows that, for a local region of 5° latitude ×10° longitude in mid-latitude regions of Australia (~30° to 40°S) with approximately 15 CORS stations, ionospheric corrections with an accuracy of 5 cm can be obtained. In Victoria and New South Wales, where dense CORS networks exist (nominal spacing of ~100 km), the average ionospheric corrections accuracy can reach 2 cm. For sparse networks (nominal spacing of >200 km) at lower latitudes, the average accuracy of the ...
This paper reviews several prevalent formats that are used to transmit GNSS data in real-time. Th... more This paper reviews several prevalent formats that are used to transmit GNSS data in real-time. This work has initiated from the research on real-time quality control for Network RTK positioning which aims to independently assess the positioning quality of users ...
High-precision global navigation satellite system (GNSS) positioning and navigation can be achiev... more High-precision global navigation satellite system (GNSS) positioning and navigation can be achieved with carrier-phase ambiguity resolution when the integer least squares (ILS) success rate (SR) is high. The users typically prefer the float solution under the scenario of having a low SR, and the ILS solution when the SR is high. The best integer equivariant (BIE) estimator is an alternative solution since it minimizes the mean squared errors (MSEs); hence, it will always be superior to both its float and ILS counterparts. There has been a recent development of GNSSs consisting of the Global Positioning System (GPS), Galileo, Quasi-Zenith Satellite System (QZSS), and the BeiDou Navigation Satellite System (BDS), which has made precise positioning with Android smartphones possible. Since smartphone tracking of GNSS signals is generally of poorer quality than with geodetic grade receivers and antennas, the ILS SR is typically less than one, resulting in the BIE estimator being the pref...
This paper examines quality and integrity issues that need to be managed in order to successfully... more This paper examines quality and integrity issues that need to be managed in order to successfully operate a real-time CORS network. Important concepts in quality control such as data availability, latency, multipath, atmospheric effects, and interference are discussed. These quality indicators are examined in the context of their capacity to indicate potential problems that can degrade the quality of real-time network positioning. The issue of intelligent alerting is raised and an alternative strategy, based on the use of relative thresholds, is proposed with the aim of reducing the number of unnecessary alerts provided to operators. South Africa’s CORS network TrigNet is used as a case study to test some of these concepts. 1.
In the last decade the use of high precision Global Navigational Satellite Systems (GNSS) has inc... more In the last decade the use of high precision Global Navigational Satellite Systems (GNSS) has increased markedly and the range of user applications has grown well beyond the traditional domain of surveying and engineering. This growth has been facilitated by the establishment of Continuously Operating Reference Station (CORS) networks and a new form of positioning known as Network Real-Time Kinematic (NRTK). However, the growth in the range of user applications has brought with it some interesting challenges for equipment manufacturers, software developers, and providers of NRTK services. One such challenge is ensuring that the quality of positioning consistently satisfies the demands of the customer. Currently there is nor reliable, nor readily available, quality indicator that can inform users as to the quality of their positioning. A further shortcoming in NRTK positioning is that the stochastic models employed are generally simplistic and overly optimistic. The consequence is th...
In 2018, a next-generation Satellite-Based Augmentation System (SBAS) test-bed was launched in Au... more In 2018, a next-generation Satellite-Based Augmentation System (SBAS) test-bed was launched in Australia/New-Zealand in preparation for building an operational system. This new generation SBAS includes L1 legacy SBAS, new dual-frequency multi-constellation (DFMC) SBAS, and orbit and clock corrections for precise point positioning (PPP) using GPS and Galileo. In this paper, the next generation SBAS and its models are first presented, and the benefits of using its new components are discussed. Test results for lane identification applications in Intelligent Transport Systems (ITS) are presented and analyzed. Kinematic tests were performed in different ITS environments. These are characterized by different levels of sky-visibility and multipath, including clear sky, suburban, low-density urban, and high-density urban environments. Performance analysis show that results vary widely depending on the operational conditions but all SBAS solutions have better positioning accuracy compared with the standalone solutions that are currently used in transport applications. The DFMC SBAS slightly outperformed the L1 SBAS, with accuracy at submeter, and it has advantages during periods of fluctuations of the ionosphere with an extended coverage area. As expected, the SBAS-based PPP solutions have shown to give the best positioning precision and accuracy among all tested solution types, with sub-decimeter level accuracy, provided that enough convergence time is available. The paper concluded by giving remarks on the use of this new technology for ITS.
The recent development of the smartphone Global Navigation Satellite System (GNSS) chipsets, such... more The recent development of the smartphone Global Navigation Satellite System (GNSS) chipsets, such as Broadcom BCM47755 and Qualcomm Snapdragon 855 embedded, makes instantaneous and cm level real-time kinematic (RTK) positioning possible with Android-based smartphones. In this contribution we investigate the instantaneous single-baseline RTK performance of Samsung Galaxy S20 and Google Pixel 4 (GP4) smartphones with such chipsets, while making use of dual-frequency L1 + L5 Global Positioning System (GPS), E1 + E5a Galileo, L1 + L5 Quasi-Zenith Satellite System (QZSS) and B1 BeiDou Navigation Satellite System (BDS) code and phase observations in Dunedin, New Zealand. The effects of locating the smartphones in an upright and lying down position were evaluated, and we show that the choice of smartphone configuration can affect the positioning performance even in a zero-baseline setup. In particular, we found non-zero mean and linear trends in the double-differenced carrier-phase residua...
This paper reports on some of the recent kinematic test results that were achieved using the L1 S... more This paper reports on some of the recent kinematic test results that were achieved using the L1 SBAS service from the Australian and New Zealand SBAS Test-bed. The paper specifically focuses on the performance of low-cost consumer-grade GNSS devices. Two devices, namely the u-blox M8N and SkyTraq Venus 838FLPx receivers were tested in walking and driving environments. The results showed that sub-metre positioning is attainable with the SBAS service and highlight the importance of matching the receiver kinematic mode to the intended use case. Additionally, these results indicate that the performance of any receiver can vary greatly depending on the combination of test environment and equipment configuration.
In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-b... more In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-based kinematic positioning in Australian urban environments are presented and analysed. As the standalone GNSS positioning is unable to deliver the accuracy required for absolute positioning in Intelligent Transport Systems (ITS), more advanced technologies are needed, and the Australian SBAS with PPP capabilities is a candidate. Kinematic tests were run in scenarios characterised by four environments: high-density urban, low-density urban, suburban and tree-canopy. SBAS positioning performance was evaluated in the different environments, with a focus on its capability to provide lane identification and thus aid ITS applications.
Journal of Atmospheric and Oceanic Technology, 2013
Near-real-time quality control procedures for temperature profiles collected from ships of opport... more Near-real-time quality control procedures for temperature profiles collected from ships of opportunity were implemented during the 1980s in oceans across the world and from the 1990s in the Mediterranean. In this sea, the procedures were originally based on seven steps (detection of end of profile, gross range check, position control, elimination of spikes, Gaussian smoothing and resampling at 1-m intervals, general malfunction control, and comparison with climatology), complemented with initial and final visual checks. The quality of data derived from a comparison with historical data (namely, climatology) depends on the availability of a huge amount of data that can statistically represent the mean characteristics of the seawater. A significant amount of data has been collected, and the existing temperature database in the Mediterranean can now provide more information on temporal and spatial variability at monthly and mesoscales, and an improved procedure for data quality control...
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
This paper provides an overview and the results of the Australia-Japan 2020 Quasi Zenith Satellit... more This paper provides an overview and the results of the Australia-Japan 2020 Quasi Zenith Satellite System (QZSS) Emergency Warning System trial project. The project aimed to evaluate and demonstrate the feasibility of utilising the QZSS system to support emergency warning and response in Australia. The trial has focussed on bushfire and tsunami warnings with an emphasis on the message structure and standards for incorporation on the available signal bandwidth, and the spatial coverage extent of the messages. It also aimed to address the need for a space-based communication capability in Australia, which could potentially facilitate effective emergency warning system unconstrained by the limitations of terrestrial telecommunications. A newly dedicated MobileApp was developed to decode the warning message and visualise relevant information on a map. Two messages for bushfire and tsunami warnings were generated in Australia and sent to the QZSS ground station for satellite transmission...
The primary goal of the project is to develop and implement a robust, independent, realtime syste... more The primary goal of the project is to develop and implement a robust, independent, realtime system that will inform users and CORS operators of the quality, dependability, and fitnessfor-purpose of NRTK positioning results. The system, dubbed the Real-Time Quality Control (RTQC) system is unique in that the quality control computations are performed and reported in real-time and the quality control process integrates CORS and mobile data. Although options exist to perform quality control analysis in a post-processed mode, no such options are available in real-time nor are they independent of proprietary algorithms.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-b... more In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-based kinematic positioning in Australian urban environments are presented and analysed. As the standalone GNSS positioning is unable to deliver the accuracy required for absolute positioning in Intelligent Transport Systems (ITS), more advanced technologies are needed, and the Australian SBAS with PPP capabilities is a candidate. Kinematic tests were run in scenarios characterised by four environments: high-density urban, low-density urban, suburban and tree-canopy. SBAS positioning performance was evaluated in the different environments, with a focus on its capability to provide lane identification and thus aid ITS applications.
The FAIR principles of Wilkinson et al. [1] are finding their way from research into application ... more The FAIR principles of Wilkinson et al. [1] are finding their way from research into application domains, one of which is the precise positioning with global satellite navigation systems (GNSS). Current GNSS users demand that data and services are findable online, accessible via open protocols (by both, machines and humans), interoperable with their legacy systems and reusable in various settings. Comprehensive metadata are essential in seamless communication between GNSS data and service providers and their users, and, for decades, geodetic and geospatial standards are efficiently implemented to support this. However, GNSS user community is transforming from precise positioning by highly specialised use by geodetic professionals to every-day precise positioning by autonomous vehicles or wellness obsessed citizens. Moreover, rapid technological developments allow alternative ways of offering data and services to their users. These transforming circumstances warrant a review whether ...
Centimetre-level accurate ionospheric corrections are required for a high accuracy and rapid conv... more Centimetre-level accurate ionospheric corrections are required for a high accuracy and rapid convergence of Precise Point Positioning (PPP) GNSS positioning solutions. This research aims to evaluate the accuracy of a local/regional ionospheric delay model using a linear interpolation method across Australia. The accuracy of the ionospheric corrections is assessed as a function of both different latitudinal regions and the number and spatial density of GNSS Continuously Operating Reference Stations (CORSs). Our research shows that, for a local region of 5° latitude ×10° longitude in mid-latitude regions of Australia (~30° to 40°S) with approximately 15 CORS stations, ionospheric corrections with an accuracy of 5 cm can be obtained. In Victoria and New South Wales, where dense CORS networks exist (nominal spacing of ~100 km), the average ionospheric corrections accuracy can reach 2 cm. For sparse networks (nominal spacing of >200 km) at lower latitudes, the average accuracy of the ...
This paper reviews several prevalent formats that are used to transmit GNSS data in real-time. Th... more This paper reviews several prevalent formats that are used to transmit GNSS data in real-time. This work has initiated from the research on real-time quality control for Network RTK positioning which aims to independently assess the positioning quality of users ...
High-precision global navigation satellite system (GNSS) positioning and navigation can be achiev... more High-precision global navigation satellite system (GNSS) positioning and navigation can be achieved with carrier-phase ambiguity resolution when the integer least squares (ILS) success rate (SR) is high. The users typically prefer the float solution under the scenario of having a low SR, and the ILS solution when the SR is high. The best integer equivariant (BIE) estimator is an alternative solution since it minimizes the mean squared errors (MSEs); hence, it will always be superior to both its float and ILS counterparts. There has been a recent development of GNSSs consisting of the Global Positioning System (GPS), Galileo, Quasi-Zenith Satellite System (QZSS), and the BeiDou Navigation Satellite System (BDS), which has made precise positioning with Android smartphones possible. Since smartphone tracking of GNSS signals is generally of poorer quality than with geodetic grade receivers and antennas, the ILS SR is typically less than one, resulting in the BIE estimator being the pref...
This paper examines quality and integrity issues that need to be managed in order to successfully... more This paper examines quality and integrity issues that need to be managed in order to successfully operate a real-time CORS network. Important concepts in quality control such as data availability, latency, multipath, atmospheric effects, and interference are discussed. These quality indicators are examined in the context of their capacity to indicate potential problems that can degrade the quality of real-time network positioning. The issue of intelligent alerting is raised and an alternative strategy, based on the use of relative thresholds, is proposed with the aim of reducing the number of unnecessary alerts provided to operators. South Africa’s CORS network TrigNet is used as a case study to test some of these concepts. 1.
In the last decade the use of high precision Global Navigational Satellite Systems (GNSS) has inc... more In the last decade the use of high precision Global Navigational Satellite Systems (GNSS) has increased markedly and the range of user applications has grown well beyond the traditional domain of surveying and engineering. This growth has been facilitated by the establishment of Continuously Operating Reference Station (CORS) networks and a new form of positioning known as Network Real-Time Kinematic (NRTK). However, the growth in the range of user applications has brought with it some interesting challenges for equipment manufacturers, software developers, and providers of NRTK services. One such challenge is ensuring that the quality of positioning consistently satisfies the demands of the customer. Currently there is nor reliable, nor readily available, quality indicator that can inform users as to the quality of their positioning. A further shortcoming in NRTK positioning is that the stochastic models employed are generally simplistic and overly optimistic. The consequence is th...
In 2018, a next-generation Satellite-Based Augmentation System (SBAS) test-bed was launched in Au... more In 2018, a next-generation Satellite-Based Augmentation System (SBAS) test-bed was launched in Australia/New-Zealand in preparation for building an operational system. This new generation SBAS includes L1 legacy SBAS, new dual-frequency multi-constellation (DFMC) SBAS, and orbit and clock corrections for precise point positioning (PPP) using GPS and Galileo. In this paper, the next generation SBAS and its models are first presented, and the benefits of using its new components are discussed. Test results for lane identification applications in Intelligent Transport Systems (ITS) are presented and analyzed. Kinematic tests were performed in different ITS environments. These are characterized by different levels of sky-visibility and multipath, including clear sky, suburban, low-density urban, and high-density urban environments. Performance analysis show that results vary widely depending on the operational conditions but all SBAS solutions have better positioning accuracy compared with the standalone solutions that are currently used in transport applications. The DFMC SBAS slightly outperformed the L1 SBAS, with accuracy at submeter, and it has advantages during periods of fluctuations of the ionosphere with an extended coverage area. As expected, the SBAS-based PPP solutions have shown to give the best positioning precision and accuracy among all tested solution types, with sub-decimeter level accuracy, provided that enough convergence time is available. The paper concluded by giving remarks on the use of this new technology for ITS.
The recent development of the smartphone Global Navigation Satellite System (GNSS) chipsets, such... more The recent development of the smartphone Global Navigation Satellite System (GNSS) chipsets, such as Broadcom BCM47755 and Qualcomm Snapdragon 855 embedded, makes instantaneous and cm level real-time kinematic (RTK) positioning possible with Android-based smartphones. In this contribution we investigate the instantaneous single-baseline RTK performance of Samsung Galaxy S20 and Google Pixel 4 (GP4) smartphones with such chipsets, while making use of dual-frequency L1 + L5 Global Positioning System (GPS), E1 + E5a Galileo, L1 + L5 Quasi-Zenith Satellite System (QZSS) and B1 BeiDou Navigation Satellite System (BDS) code and phase observations in Dunedin, New Zealand. The effects of locating the smartphones in an upright and lying down position were evaluated, and we show that the choice of smartphone configuration can affect the positioning performance even in a zero-baseline setup. In particular, we found non-zero mean and linear trends in the double-differenced carrier-phase residua...
This paper reports on some of the recent kinematic test results that were achieved using the L1 S... more This paper reports on some of the recent kinematic test results that were achieved using the L1 SBAS service from the Australian and New Zealand SBAS Test-bed. The paper specifically focuses on the performance of low-cost consumer-grade GNSS devices. Two devices, namely the u-blox M8N and SkyTraq Venus 838FLPx receivers were tested in walking and driving environments. The results showed that sub-metre positioning is attainable with the SBAS service and highlight the importance of matching the receiver kinematic mode to the intended use case. Additionally, these results indicate that the performance of any receiver can vary greatly depending on the combination of test environment and equipment configuration.
In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-b... more In this study, the first results of the next-generation dual-frequency multi-constellation SBAS-based kinematic positioning in Australian urban environments are presented and analysed. As the standalone GNSS positioning is unable to deliver the accuracy required for absolute positioning in Intelligent Transport Systems (ITS), more advanced technologies are needed, and the Australian SBAS with PPP capabilities is a candidate. Kinematic tests were run in scenarios characterised by four environments: high-density urban, low-density urban, suburban and tree-canopy. SBAS positioning performance was evaluated in the different environments, with a focus on its capability to provide lane identification and thus aid ITS applications.
Journal of Atmospheric and Oceanic Technology, 2013
Near-real-time quality control procedures for temperature profiles collected from ships of opport... more Near-real-time quality control procedures for temperature profiles collected from ships of opportunity were implemented during the 1980s in oceans across the world and from the 1990s in the Mediterranean. In this sea, the procedures were originally based on seven steps (detection of end of profile, gross range check, position control, elimination of spikes, Gaussian smoothing and resampling at 1-m intervals, general malfunction control, and comparison with climatology), complemented with initial and final visual checks. The quality of data derived from a comparison with historical data (namely, climatology) depends on the availability of a huge amount of data that can statistically represent the mean characteristics of the seawater. A significant amount of data has been collected, and the existing temperature database in the Mediterranean can now provide more information on temporal and spatial variability at monthly and mesoscales, and an improved procedure for data quality control...
ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, 2020
This paper provides an overview and the results of the Australia-Japan 2020 Quasi Zenith Satellit... more This paper provides an overview and the results of the Australia-Japan 2020 Quasi Zenith Satellite System (QZSS) Emergency Warning System trial project. The project aimed to evaluate and demonstrate the feasibility of utilising the QZSS system to support emergency warning and response in Australia. The trial has focussed on bushfire and tsunami warnings with an emphasis on the message structure and standards for incorporation on the available signal bandwidth, and the spatial coverage extent of the messages. It also aimed to address the need for a space-based communication capability in Australia, which could potentially facilitate effective emergency warning system unconstrained by the limitations of terrestrial telecommunications. A newly dedicated MobileApp was developed to decode the warning message and visualise relevant information on a map. Two messages for bushfire and tsunami warnings were generated in Australia and sent to the QZSS ground station for satellite transmission...
Part III -Quality Indicators and Stochastic Modelling • Conclusions and Future Work 2 Outline Par... more Part III -Quality Indicators and Stochastic Modelling • Conclusions and Future Work 2 Outline Part I Background and Introduction to RTQC • Use of high accuracy GNSS has increased markedly in the last decade • Range of applications has grown beyond surveying & engineering • Facilitated by CORS Networks and Network RTK • Critical decisions based on GNSS have increased as a result • Challenges for CORS providers, manufacturers, researchers 4 Project Background • Ensuring GNSS derived positions are -High quality -Dependable -Fit-for-purpose • Current Quality indicators are not always reliable • Generally a measure of precision is conveyed -Often overestimated -Precision is not accuracy 5
Uploads
Papers by Eldar Rubinov