A Fast-Developing All-Sky Meteor Surveillance Network in China

Ground-based meteor surveillance network is the most widely used technique to monitor meteors. We report a newly developed optical meteor surveillance network in China, named the Large Automated Network of Remote All-sky Observatories (LANRAO) for Meteor Surveillance. Our goal is to support a comprehensive study of the dynamic meteoroid environment in near-Earth space. The objectives are 1) Providing nearly continuous monitoring of meteors and precisely determining their 3D trajectories; 2) Discovering new meteor streams and identifying their parent bodies, especially those associated with asteroidal objects; 3) Detecting potential unknown long-period comet impactors to Earth; and 4) Studying the evolution of meteor streams and their contribution to the zodiacal cloud. Additionally, the network will support citizen science, public outreach, and education. The system is composed of a network of self-developed, all-sky cameras and an automated data center. With a limiting magnitude of 4.2 for stars, the cameras can take all-sky images at a frequency of up to 30 Hz, and automatically identify meteors and measure the astrometry using the onboard software. The data center combines the measurements and GPS-based time tags from multiple stations to reconstruct the 3D trajectories and velocities of meteors. The brightness of meteors is estimated with relative photometry utilizing star catalogs. The results are visualized in nearly real-time. A testing network was installed in Beijing in 2023 and has since been operated for one year and detected 7253 meteors, including both sporadic and 225 streams. A full-scale network that currently contains 14 stations was deployed in Guangdong Province and Hong Kong and Macau SARs in December 2023, covering an area of over 180,000 km². It has successfully observed the Geminids and the Quadrantids meteor showers. In the long term, we plan to expand the network to cover whole China, increase the sensitivity, and add multiband imaging and eventually spectroscopic capability. We also plan to combine this optical network with various atmospheric radars and ionospheric radars already constructed in China to expand the area, temporal, and size coverages of meteors.