Concluding Performance Self-Evaluation M...

On January 20, 2026, the concluding performance self-evaluation meeting for the project “Key Technologies and Application Verification of Component-Based Resilient Integrated Navigation and Control”, under the National Key R&D Program “Earth Observation and Navigation” Key Special Project, was successfully held in Wuhan in a hybrid online-offline format. The meeting was hosted by Wuhan University, the leading institution of the project, and chaired by Project Responsible Expert Researcher Zhu Yanbo.Academician Liu Jingnan of Wuhan University (online), Deputy Director Wang Xiaochuan of the Research Project Management Office, Science and Technology Development Research Institute of Wuhan University, Professor Lou Yidong, Deputy Director of the Research Center for Satellite Navigation and Positioning Technology of Wuhan University, as well as members of the project evaluation expert panel—including Researcher Zhu Yanbo from Civil Aviation Data Communication Co., Ltd., Professor Li Bofeng from Tongji University (online), Professor Lu Mingquan from Tsinghua University, Researcher Yuan Yunbin from the Innovation Academy for Precision Measurement Science and Technology of the Chinese Academy of Sciences, Professor Xu Tianhe from Shandong University, Professor Wei Jiaolong from Huazhong University of Science and Technology, and Professor Chu Duanfeng from Wuhan University of Technology—were invited to attend the meeting. More than 30 representatives, including principal investigators of the project subtasks and participants from collaborating institutions, also took part in the meeting.During the comprehensive performance evaluation session, Professor Geng Jianghui of Wuhan University (Subtask 1), Professor Wu Yuanxin of Shanghai Jiao Tong University (Subtask 2), Researcher Shi Hang of ZJU Lab (Subtask 3), and Professor Cheng Hui of Sun Yat-sen University (Subtask 4) delivered systematic presentations on their respective research contents, major achievements, and completion status of assessment indicators.The expert panel conducted in-depth discussions focusing on key technological progress, quality of research outcomes, and application prospects of the subtasks. After comprehensive evaluation, the panel unanimously agreed that all subtasks had fulfilled the objectives and requirements specified in the task assignments, with complete research outcomes and satisfactory performance indicators, and approved the comprehensive performance evaluation. The experts also recommended further strengthening the synthesis and refinement of research outcomes to lay a more solid foundation for subsequent project evaluation and application.At the conclusion of the meeting, Project Leader Professor Geng Jianghui expressed sincere gratitude to the expert panel for their valuable guidance and suggestions, and emphasized that all subtask teams should carefully implement the experts’ recommendations, continue advancing related research and outcome refinement, and further enhance the project’s contribution to national major strategic needs.

Successful Holding of the Academic Semin...

On December 25, 2025, Dr. Yixin Xiao from The Ohio State University delivered an academic lecture entitled "Harnessing Coherent Reflection for GNSS Bistatic Radar Altimetry"at the Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Science. The lecture was hosted by Prof. Jianghui Geng and held in Room 206, Building 3.In the presentation, Dr. Xiao introduced recent advances in GNSS Reflectometry (GNSS-R) for satellite altimetry, focusing on challenges such as weak reflected signals and limited radial orbit accuracy. A frequency-domain phase reconstruction method and a dual-satellite crossover adjustment strategy were presented and validated using CYGNSS and Spire Global data, achieving altimetric accuracies better than 10 cm.。After the lecture, participating faculty members and students engaged in discussions on GNSS-R theory, signal processing techniques, and approaches to further improve altimetric accuracy.

Kick-off Meeting of Task Force for The F...

On December 16, 2025 (Beijing Time), the IGS Task Force for the format standard of the combination statistics held its online Kick-off Meeting. Chaired by Prof. Jianghui Geng, the meeting aimed to establish the strategic direction and planning for the new generation of combination statistical standard formats. The discussion focused on four key technical topics: 1) the logical basis for the primary classification index (Analysis Center name vs. product type); 2) selection of the combination standard format; 3) the necessity of including multi-frequency signal biases in the statistical scope; and 4) the feasibility of integrating ERP combination information.It was noted that the traditional combination files separate orbit and clock information, failing to meet the demands of Analysis Centers for refined quality monitoring and the requirements of PPP users for high-precision and high-reliability positioning. Consequently, the meeting established three core goals for the new standard: 1) facilitating Analysis Centers in troubleshooting product issues; 2) assisting PPP users in excluding outliers in orbits, clocks, and biases; and 3) developing auxiliary tools for plotting combination statistics. Furthermore, the meeting outlined the architecture of the new format, which will encompass: metadata (antenna models, combination strategies, reference frequencies, sampling rates, etc.), orbit statistics (Helmert transformation parameters, radial/along-track/cross-track errors, system time, etc.), as well as clock statistics (weights, excluded epochs, offsets, RMSE, etc.) and bias statistics. Following in-depth discussions, the meeting decided to integrate ERP combination information and consider the inclusion of coordinate combination content. Ultimately, "product type" was established as the primary classification logic, and three formats—SINEX, JSON, and YAML—were selected for subsequent testing and evaluation.Representatives from various IGS Analysis Centers, as well as experts and scholars in the field of precision positioning from around the globe, attended the Kick-off Meeting. Through this meeting, the Task Force further consolidated technical consensus on the new generation of combination statistical formats and defined the implementation path, laying a solid foundation for modernizing IGS data standards and supporting high-precision GNSS applications.

Successful Holding of the Academic Semin...

On the morning of 26 November 2025, the academic seminar “GNSS Atmospheric Remote Sensing: A Feasibility Study of Detecting Atmospheric Turbulence”, hosted by the Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, was successfully held in Meeting Room 206, Building 3, East Lake Campus. The seminar was chaired by Researcher Jianghui Geng, and Professor Zhiguo Deng of Liaoning Technical University served as the keynote speaker.First, Professor Zhiguo Deng delivered a presentation titled “GNSS Atmospheric Remote Sensing: A Feasibility Study of Detecting Atmospheric Turbulence.” At the beginning of the talk, Professor Deng explained the objectives of turbulence research, including supporting weather and atmospheric forecasting, aviation safety assurance, studies of atmospheric governance and pollutant dispersion, and wind-energy development. He then gave a detailed introduction to the principle by which GNSS electromagnetic signals experience refractive delay when traversing the troposphere, and how high-frequency fluctuation information contained in the wet delay component—Zenith Wet Delay (ZWD)—can be used to study atmospheric turbulence characteristics. In the presentation, Professor Deng showed results of spectral analysis and turbulence-parameter extraction from ZWD time series based on continuous observations from multi-system GNSS. Using the von Kármán turbulence spectrum model, and by fitting the ZWD power spectral density, two key parameters were retrieved: the fluctuation variance σ² and the cutoff frequency α. Combined with lidar and Sentinel satellite imagery for detailed, systematic analysis, the results indicate that both σ² and α derived from ZWD exhibit pronounced seasonal variations and closely follow changes in cloudiness and turbulent kinetic energy (TKE), peaking notably during convectively active summer periods. In addition, a four-hour sliding-window analysis revealed that short-term variations in α and σ² respond to rapid adjustments in wind speed and boundary-layer structure, thereby exposing multi-timescale turbulence features hidden in GNSS wet-delay signals. This study offers a new perspective for GNSS meteorology and opens a new avenue for monitoring atmospheric turbulence.After the presentation, participants engaged in in-depth discussions on topics such as applications of GNSS atmospheric remote-sensing technology and methods for extracting turbulence parameters, and they looked forward to future research. Suggestions included applying atomic clocks in the observation process to reduce the impact of clock bias, and mitigating multipath effects to further purify turbulence power spectra. Attending experts and scholars exchanged deeply on technology application bottlenecks, data-processing methods, and future research directions; the interplay of differing viewpoints broadened ideas for subsequent scientific collaboration and for solving technical challenges.The successful holding of this seminar not only promoted academic exchange on GNSS technology in the field of atmospheric remote sensing, but also provided a valuable learning platform for researchers in related fields. Participants unanimously agreed that Professor Deng’s report was detailed and insightful, playing an important leading role in GNSS atmospheric remote-sensing research and even opening up a novel research direction that will positively drive future work in related fields. 

The Inaugural Meeting of the IGS BAR Com...

On October 29, 2025 (Beijing Time), the IGS Bias and Ambiguity Resolution (BAR) Committee convened its inaugural meeting. The BAR Committee, which integrates the former "Bias & Calibration Working Group" and "the PPP-AR Pilot Project", has its core objective of coordinating the research, standardization, validation, and dissemination of satellite bias products for existing GNSS and future LEO satellites. Researcher Jianghui Geng from the PRIDE Research Group chaired the inaugural meetings. Dr. Wen Qiang from the PRIDE Research Group delivered a report titled Progress Report of the PPP-AR Pilot Project for 2024/2025, reviewing the work of the PPP-AR Pilot Project over the past year regarding orbit/clock/biases products. This year, BDS-3 PPP-AR product was included in the final combined product, thanks to the release of the HUS final BDS products. PPP-AR products from other Analysis Centers (ACs) of the IGS have also been updated. Specifically, EMR provides GPS code and phase OSBs in its OPS final products. WUM’s MGEX final products include QZSS phase OSBs, while GFZ MGEX rapid and GRG MGEX final products include code and phase OSBs for BDS satellites with PRN numbers higher than C46 (C47-C50).Additionally, during the meeting, Lotfi Massarweh from Delft University of Technology introduced the background, core objectives, work tasks, and charter of the newly established BAR Committee. Peter Steigenberger from the German Aerospace Center shared his research findings on the impact of GPS Flexible Power on the continuity of DCB estimation. Dr. Jiang Guo from the International Bureau of Weights and Measures presented his research on time transfer using continuous precise products.In the final discussion session of the meeting, participants focused on the future core work directions, technical challenges, and user needs of the IGS-BAR Committee. Key topics included GNSS flexible power, day-boundary bias handling methods, phase biases quality, and the development of the BAR official website.Over 60 experts, scholars, and researchers in the field of GNSS precise positioning from around the world attended the inaugural meeting. Through this meeting, all participants gained a clearer understanding of the BAR Committee’s work directions, PPP-AR technology progress, and the application of biases products. This will provide important guidance for the subsequent upgrade of GNSS high-precision services and the support for the development of LEO system.