Zhizhao Liu


Department of Land Surveying & Geo-Informatics (LSGI)

lszzliu [at] polyu.edu.hk


181 Chatham Road South
Hong Kong, KC China
Hong Kong

Brief Biography

Dr. George Zhizhao Liu is an internationally recognized expert in the Global Positioning System (GPS)/Global Navigation Satellite Systems (GNSS) community. He has 20+ years of professional experience in the GPS/GNSS Research & Development (R&D) in both academia and industry. Currently he is an Associate Professor at the Department of Land Surveying & Geo-Informatics, The Hong Kong Polytechnic University (PolyU), Hong Kong, P. R. China.

His Micro-Laboratory of Atmospheric Research and Geomatics Engineering (Micro-LARGE) Lab mainly focuses on pioneering work in the areas of GPS/GNSS innovative algorithm development, lower atmosphere water vapor modeling, and upper atmosphere ionosphere and space weather studies. The Micro-LARGE Lab has impacted the international GPS/GNSS community and beyond. His innovative algorithm of GPS/GNSS cycle slip detection and repairing, fundamental for all the GPS/GNSS precise applications in the world, is widely used by many international research groups. His work on ionosphere has revealed a two-decade-long anomaly associated with the GPS satellite’s broadcast ionospheric model and has a worldwide impact on the GPS/GNSS product manufacturing and user applications. His paper on atmospheric water vapor was among the finalists for the WMO “Norbert Gerbier-MUMM International Award for 2015”. He was the recipient of the inaugural “Early Career Award” of the Hong Kong Research Grants Council in 2012.

His Micro-LARGE Lab has established many state-of-the-art facilities in Hong Kong and Mainland China to support the Lab’s exploratory research work. The Micro-LARGE established Hong Kong’s first GPS/GNSS-based ionosphere scintillation monitoring system in 2012, Hong Kong’s first GPS/GNSS and Radiosonde Water Vapor Observation Co-location System in 2013, China’s first GPS-PPP-based (Precise Point Positioning) Atmospheric Precipitable Water Vapor Real-Time Monitoring System (PWVRMS) for the Pearl-River-Delta (PRD) Region in 2013, a Hong Kong-Wuhan University’s first CMACast Meteorological Satellite Data Receiving station at Hong Kong in 2015, and the Hong Kong-Chinese Academy of Sciences (CAS)’s first joint low-latitude ionosphere scintillation monitoring station at Sanya in 2015.

Dr. Liu currently serves as the secretary of the Sub-Commission 4.4 - Multi-Constellation GNSS of the International Association of Geodesy, Task Team Member of the GNSS Precipitable Water (GNSS-PW) Task, The Global Climate Observing System (GCOS) Reference Upper Air Network (a joint force of the World Meteorological Organization (WMO), the Intergovernmental Oceanographic Commission (IOC) of UNESCO, the United Nations Environment Programme (UNEP), and the International Council for Science (ICSU)). He served as the International Advisory Board for the U.S. Institute of Navigation (ION) Pacific Position, Navigation and Time (PNT) conference, Hawaii, USA in 2015 and served as invited speakers for many national/international conferences. He is an invited reviewer of 30+ SCI journals and many national/international research programs/fellowships including Australian Research Council (ARC), Natural Sciences and Engineering Research Council of Canada (NSERC), China State High-Tech Development Plan (“863 Program”), China NSFC, and EU’s Horizon 2020. He is a Member of Editorial Board of “GPS Solutions” and the Managing Editor of Journal of Global Positioning Systems. As PI or Co-PI, he has secured research fund of about US$4.5 M. He is the author of ~100 technical papers, ~70 of which are peer-reviewed ones. His H-index is 19.


Physical Science

Science Specialties

GPS/GNSS, water vapor observation, geodesy

Current Research

GPS/GNSS based water vapor remote sensing; water vapor observation from remote sensing satellites