Prof. George Zhizhao Liu (left) from the Department of Land Surveying and Geo-Informatics (LSGI), The Hong Kong Polytechnic University (PolyU) and Prof. Yongqiang Hao (right) from School of Atmospheric Sciences, Sun Yat-Sen University, Guangzhou.
The Receiver of Ionospheric High-Frequency Doppler Monitor (IHFDM)
On June 6, 2023, the Chinese Meridian Project, a multi-billion-yuan National Major Science and Technology Infrastructure Project funded by the National Development and Reform Commission, China, installed its first instrument in Hong Kong, in partnership with Prof. George Zhizhao Liu from the Department of Land Surveying & Geo-Informatics (LSGI), Faculty of Construction and Environment (FCE), The Hong Kong Polytechnic University (PolyU).
This instrument, named Ionospheric High-Frequency Doppler Monitor (IHFDM), is the first instrument ever installed in Hong Kong by the Chinese Meridian Project. Ionospheric high-frequency Doppler monitor is a classic technique to use continuous and stable short-wave standard frequency signals to observe and estimate the vertical movement of the ionosphere. The ionosphere, located approximately 60 km to 2,000 km above the Earth surface, has a crucially important impact on satellite navigation such as GPS and Beidou, ground- and space-based communication, and space programs. The IHFDM can be used to study the disturbances and irregularities in the ionosphere, ionospheric response to solar flares, ionospheric disturbances caused by magnetic storms and typhoons in China.
Investigating the ionosphere on satellite navigations such as the Global Navigation Satellite System (GNSS) is one of the major research areas in relation with the Micro-Laboratory of Atmospheric Research and Geomatics Engineering (Micro-LARGE), led by Prof. Liu at the PolyU. His group has been working on the ionosphere scintillation characteristics and the impact on GNSS positioning and navigation for more than one decade. His Lab was the first one in the world to use satellite signals from all the four GNSS constellations to study ionosphere scintillation.
The Chinese Meridian Project is a major national project for space weather science and infrastructure development in China. This project aims to explore the propagation, evolution, and impact of space weather events on China’s space by monitoring the space from the solar atmosphere to near-Earth over the whole China with a high spatiotemporal resolution. As the southernmost station, the Hong Kong observation station will play a significant role in realizing the scientific and application goals of this project.
