Precise Point Positioning
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Basic performance and future developments of BeiDou global navigation satellite system Open
The core performance elements of global navigation satellite system include availability, continuity, integrity and accuracy, all of which are particularly important for the developing BeiDou global navigation satellite system (BDS-3). Thi…
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Generation of real‐time mode high‐resolution water vapor fields from GPS observations Open
Pointwise GPS measurements of tropospheric zenith total delay can be interpolated to provide high‐resolution water vapor maps which may be used for correcting synthetic aperture radar images, for numeral weather prediction, and for correct…
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Assessment of Dual Frequency GNSS Observations from a Xiaomi Mi 8 Android Smartphone and Positioning Performance Analysis Open
On May 2018 the world’s first dual-frequency Global Navigation Satellite System (GNSS) smartphone produced by Xiaomi equipped with a Broadcom BCM47755 chip was launched. It is able to receive L1/E1/ and L5/E5 signals from GPS, Galileo, Bei…
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Quality assessment of multi-GNSS orbits and clocks for real-time precise point positioning Open
An increasing number of satellites of global navigation satellite systems (GNSS) and their constant modernization allow improving positioning accuracy and enable performing the GNSS measurements in challenging environments. Since 2016, the…
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The CODE ambiguity-fixed clock and phase bias analysis products: generation, properties, and performance Open
The generation and use of GNSS analysis products that allow—particularly for the needs of single-receiver applications—precise point positioning with ambiguity resolution (PPP-AR) are becoming more and more popular. A general uncertainty c…
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GNSS techniques for real-time monitoring of landslides: a review Open
Currently, Global Navigation Satellite System (GNSS) Real-Time Kinematic positioning (RTK) and Precise Point Positioning (PPP) techniques are widely employed for real-time monitoring of landslides. However, both RTK and PPP monitoring tech…
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Implicit Cooperative Positioning in Vehicular Networks Open
Absolute positioning of vehicles is based on Global Navigation Satellite Systems (GNSS) combined with on-board sensors and high-resolution maps. In Cooperative Intelligent Transportation Systems (C-ITS), the positioning performance can be …
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Semi-tightly coupled integration of multi-GNSS PPP and S-VINS for precise positioning in GNSS-challenged environments Open
Because of its high-precision, low-cost and easy-operation, Precise Point Positioning (PPP) becomes a potential and attractive positioning technique that can be applied to self-driving cars and drones. However, the reliability and availabi…
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Precise Point Positioning Using Dual-Frequency GNSS Observations on Smartphone Open
The update of the Android system and the emergence of the dual-frequency GNSS chips enable smartphones to acquire dual-frequency GNSS observations. In this paper, the GPS L1/L5 and Galileo E1/E5a dual-frequency PPP (precise point positioni…
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Review of code and phase biases in multi-GNSS positioning Open
A review of the research conducted until present on the subject of Global Navigation Satellite System (GNSS) hardware-induced phase and code biases is here provided. Biases in GNSS positioning occur because of imperfections and/or physical…
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Multi-GNSS precise point positioning for precision agriculture Open
The main objective of this research was to examine the feasibility of Multi-GNSS precise point positioning (PPP) in precision agriculture (PA) through a series of experiments with different working modes (i.e. stationary and moving) under …
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Precise GNSS Positioning Using Smart Devices Open
The recent access to GNSS (Global Navigation Satellite System) phase observations on smart devices, enabled by Google through its Android operating system, opens the possibility to apply precise positioning techniques using off-the-shelf, …
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PPP models and performances from single- to quad-frequency BDS observations Open
Nowadays, China BeiDou Navigation Satellite System (BDS) has been developed well and provided global services with highly precise positioning, navigation and timing (PNT) as well as unique short-message communication, particularly global s…
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Three-frequency BDS precise point positioning ambiguity resolution based on raw observables Open
All BeiDou navigation satellite system (BDS) satellites are transmitting signals on three frequencies, which brings new opportunity and challenges for high-accuracy precise point positioning (PPP) with ambiguity resolution (AR). This paper…
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Initial Assessment of Precise Point Positioning with LEO Enhanced Global Navigation Satellite Systems (LeGNSS) Open
The main challenge of precise point positioning (PPP) applications is the long convergence time of typically a half hour, or even more, to achieve centimeter accuracy. Even when the multi-constellation is involved and ambiguity resolution …
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LEO Enhanced Global Navigation Satellite System (LeGNSS): progress, opportunities, and challenges Open
With the completion of Chinese BeiDou Navigation Satellite System (BDS), the world has begun to enjoy the Positioning, Navigation, and Timing (PNT) services of four Global Navigation Satellite Systems (GNSS). In order to improve the GNSS p…
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Review of PPP–RTK: achievements, challenges, and opportunities Open
The PPP–RTK method, which combines the concepts of Precise of Point Positioning (PPP) and Real-Time Kinematic (RTK), is proposed to provide a centimeter-accuracy positioning service for an unlimited number of users. Recently, the PPP–RTK t…
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Global Ionospheric Modelling using Multi-GNSS: BeiDou, Galileo, GLONASS and GPS Open
The emergence of China’s Beidou, Europe’s Galileo and Russia’s GLONASS satellites has multiplied the number of ionospheric piercing points (IPP) offered by GPS alone. This provides great opportunities for deriving precise global ionospheri…
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Real-time GNSS precise point positioning for low-cost smart devices Open
Global Navigation Satellite System raw measurements from Android smart devices make accurate positioning possible with advanced techniques, e.g., precise point positioning (PPP). To achieve the sub-meter-level positioning accuracy with low…
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Towards Robust GNSS Positioning and Real-time Kinematic Using Factor Graph Optimization Open
Global navigation satellite systems (GNSS) are one of the utterly popular\nsources for providing globally referenced positioning for autonomous systems.\nHowever, the performance of the GNSS positioning is significantly challenged in\nurba…
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GPS precise point positioning for UAV photogrammetry Open
The use of Global Positioning System ( GPS ) precise point positioning ( PPP ) on a fixed‐wing unmanned aerial vehicle ( UAV ) is demonstrated for photogrammetric mapping at accuracies of centimetres in planimetry and about a decimetre in …
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New Method for Positioning Using IRIDIUM Satellite Signals of Opportunity Open
The global navigation satellite system (GNSS) system has a number of disadvantages such as weak signal strength and high cost, while signals of opportunity (SOPs) can make up for these shortcomings. Non-GNSS satellite SOPs offer some advan…
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Multi-GNSS PPP-RTK: From Large- to Small-Scale Networks Open
Precise point positioning (PPP) and its integer ambiguity resolution-enabled variant, PPP-RTK (real-time kinematic), can benefit enormously from the integration of multiple global navigation satellite systems (GNSS). In such a multi-GNSS l…
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Assessment of Multiple GNSS Real-Time SSR Products from Different Analysis Centers Open
The real-time State Space Representation (SSR) product of the GNSS (Global Navigation Satellite System) orbit and clock is one of the most essential corrections for real-time precise point positioning (PPP). In this work, the performance o…
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Optimal Walker Constellation Design of LEO-Based Global Navigation and Augmentation System Open
Low Earth orbit (LEO) satellites located at altitudes of 500 km~1500 km can carry much stronger signals and move faster than medium Earth orbit (MEO) satellites at about a 20,000 km altitude. Taking advantage of these features, LEO satelli…
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GNSS observable-specific phase biases for all-frequency PPP ambiguity resolution Open
An unwritten rule to resolve GNSS ambiguities in precise point positioning (PPP-AR) is that users should follow faithfully the frequency choices and observable combinations mandated by satellite clock and phase bias providers. Switching to…
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GPS and GLONASS observable-specific code bias estimation: comparison of solutions from the IGS and MGEX networks Open
Different from differential code biases, the observable-specific code biases (OSBs) directly describe the biases of individual pseudorange measurements, which provide full flexibilities for multi-GNSS code biases handling. We present the m…
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Evaluation of Ionospheric Delay Effects on Multi-GNSS Positioning Performance Open
Ionospheric delay is a significant error source in multi-GNSS positioning. We present different processing strategies to fully exploit the ionospheric delay effects on multi-frequency and multi-GNSS positioning performance, including stand…
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Validation and Assessment of Multi-GNSS Real-Time Precise Point Positioning in Simulated Kinematic Mode Using IGS Real-Time Service Open
Precise Point Positioning (PPP) is a popular technology for precise applications based on the Global Navigation Satellite System (GNSS). Multi-GNSS combined PPP has become a hot topic in recent years with the development of multiple GNSSs.…
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Ionosphere-weighted undifferenced and uncombined PPP-RTK: theoretical models and experimental results Open
Precise ionospheric information, as like precise satellite orbits, clocks, and code/phase biases, is a critical factor for achieving fast integer ambiguity resolution in precise point positioning (PPP-AR). This study develops an ionosphere…