Satellite Navigation

• Satellite Navigation ranks 2/52 (Q1) in Engineering, Aerospace in the 2025-released JCR.
• Special acknowledgement goes to our outstanding reviewers in 2024
• Enjoy All the 2024 Contents of Satellite Navigation
• Top 10 Downloaded and Most Cited Articles Published in 2024 and 2023.

GNSS techniques for real-time monitoring of landslides: a review

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 techniques have their limitations, such as limited service coverage or long convergence times. PPP-RTK technique which integrates RTK and PPP is a novel approach for monitoring landslides with the advantages of rapid convergence, high-precision, and a wide service area. This study summarizes the limitations of RTK, PPP, and PPP-RTK monitoring techniques and suggests some improved strategies. Their performances are compared and analyzed using real monitoring data. The experiment results demonstrate that RTK is the best option for small-scale (the baseline distance < 15 km) and real-time landslide monitoring without considering the cost. PPP technique converges to centimeter-level accuracy in tens of minutes, only suitable for the stability analysis of reference stations. Over a large area (the baseline distance < 100 km), PPP-RTK can provide excellent horizontal accuracy and adapt the service range in response to the demand for monitoring accuracy, as the vertical accuracy is significantly impacted by the service range and elevation difference. Finally, the characteristics of three techniques are integrated to form a comprehensive landslide monitoring technique that considers intelligence, robustness, and real-time.

Multi-frequency smartphone positioning performance evaluation: insights into A-GNSS PPP-B2b services and beyond

In August 2023, Xiaomi unveiled the Redmi K60 Ultra, the first multi-frequency smartphone integrated with BeiDou-3 Navigation Satellite System Precise Point Positioning (PPP-B2b) services and employing PPP technology as the primary positioning method. The positioning enhancement service is provided by the Assisted Global Navigation Satellite System (A-GNSS) location platform developed by the China Academy of Information and Communications Technology. The signaling interaction between the server and the users strictly adheres to the Third Generation of Mobile Communications Technology Partnership Project Long-Term Evolution Positioning Protocol and the Open Mobile Alliance Secure User Plane Location framework. To comprehensively evaluate the Redmi K60 Ultra’s capabilities, this study designed six distinct experimental scenarios and conducted comprehensive research on multi-frequency and multi-GNSS observation noise, Time to First Fix (TTFF), as well as the performance of both GNSS-based and network-based positioning. Experimental results indicate that the GNSS chipset within the Redmi K60 Ultra has achieved a leading position in the consumer market concerning supported satellite constellations, frequencies, and observation accuracy, and is comparable to some low-cost GNSS receivers. A-GNSS positioning can reduce the TTFF from 30 to under 5 s, representing an improvement of over 85% in the cold start speed compared to a standalone GNSS mode. The positioning results show that the A-GNSS PPP-B2b service can achieve positioning performance with RMS errors of less than 1.5 m, 2.5 m, and 4 m in open-sky, realistic, and challenging urban environments. Compared to GNSS-based positioning, cellular network-based Observed Time Difference of Arrival (OTDOA) positioning achieves an accuracy ranging from tens to hundreds of meters in various experimental scenarios and currently functions primarily as coarse location determination. Additionally, this study explores the potential of the Three-Dimensional Mapping-Aided (3DMA) GNSS algorithm in detecting Non-Line-of-Sight signals and enhancing positioning performance. The results indicate that 3DMA PPP, as compared to conventional PPP, can significantly accelerate PPP convergence and improve positioning accuracy by over 30%. Consequently, 3D city models can be utilized as future assistance data for the A-GNSS location platform.

Check our newest content on the following topics:

• BDS/GNSS: New Development, Progress and Applications 
  This special issue is open to all scientists who may have the latest results and developments in BDS/GNSS+, including constellation, signal, orbit, receiver and new scientific applications. 
• GNSS PPP and PPP-RTK
  This special issue is mainly for the new theory, method and application in real-time PPP and PPP-RTK.
• GNSS Applications in Geosciences
  This special issue invites papers that cover ongoing efforts to broaden the GNSS applications to all possible fields relevant to geosciences, especially in natural hazard monitoring. 
• Ubiquitous Positioning, Navigation and Timing for Location Based Services 
  The aim of this special issue is to collect the new theory, method and application for the ubiquity of PNT in GNSS challenging environments.  
• Navigation Technologies for Autonomous Systems
  This special issue accepts contributions covering advanced topics related to the state of the art and future trends of navigation technologies and algorithms for safe navigation of autonomous systems. 
• GNSS Ionospheric Monitoring and Modelling 
  This special issue is mainly for the new theory, method and application in real-time GNSS monitoring and modeling.
• Ubiquitous Positioning, Indoor Navigation and Location-Based Services
  At UPINLBS, we concentrate on innovative, state-of-the-art solutions and techniques dealing with ubiquitous positioning, indoor navigation, location-based technologies, and so much more! UPINLBS will feature leading minds from relevant industries, and provide an indispensable platform for networking with like-minded individuals, researchers, developers, and businesses.
• BDS/GNSS high-precision products: strategies, services, and applications 
  This special issue is an assemblage of research aiming to cover the strategies used for high-precision products of BDS/GNSS constellations and its applications in geosciences as well as mass massive market. 
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Following the rapid economic growth in China over the last 30 years, there is now a strong desire to promote the development and propagation of science and technology for the long-term future. Recognizing the importance of academic journals in disseminating research results and inspiring new research ideas as well as strengthening communication, AIRCAS will sponsor Satellite Navigation as an international platform, providing researchers and engineers in navigation, positioning and timing with a unique opportunity to closely interact and communicate. This journal will not only provide a venue for in-depth scientific exchanges, but also seek to promote research collaborations and exploit international funding sources, especially those involving China. See full text. 

Yuanxi Yang serves as Academician of the Chinese Academy of Sciences for his lifelong contributions to navigation, geodetic science and engineering. Currently, he is Professor of Geodesy and Navigation at Xi’an Research Institute of Surveying and Mapping and serves at China National Administration of GNSS and Application (CNAGA). He is also Head of State Key Laboratory Of Geo-information Engineering, adjunct professor and PhD Tutor in Beihang University.
He acted as deputy chief designer of China’s BeiDou Navigation Satellite System (BDS), and has been a leading member of BDS advisory board since its inception in 2010. He originally developed the Robust Parameter Estimation for Geodetic Correlated Observations and adaptive navigation and kinematic positioning. He is credited with improving the design of the interlink between BeiDou satellites, the establishment of the Chinese Geodetic Coordinate System, the creation of the Chinese National GPS Control Network, and is a prominent proponent of interoperability between BeiDou and other GNSSs.
" The continuous development of global and regional satellite navigation systems provides an important basis for the integrated applications of multi-satellite navigation. The Journal aims to disseminate the latest achievements of satellite navigation, discuss different academic views and promote the progress of technology and applications. I hope Satellite Navigation will build an academic exchange platform for all researchers." Said Prof. Yuanxi Yang.