Astronomical Observing Site Selection on the Tibetan Plateau—Lenghu: A Site Capable of Hosting the Future Development of Optical Astronomy in China

Starting in the early 2000s, China's astronomical community undertook a strategic survey for optical observing sites in the broader Qinghai-Tibet Plateau region. In 2016, site-specific monitoring was conducted based on the preliminary work for the 13th Five-Year Plan's major scientific engineering projects, including the plan of a 10 meter Large Optical/Infrared Telescope (LOT). Although not selected as a candidate site, this spurred the site survey in the Lenghu area. Since 2018, continuous site-specific monitoring of Lenghu has been carried out, yielding continuous data on site quality parameters under seeing limited conditions. Data shows that the site quality of the Saishiteng Mountain in Lenghu is excellent and meets the needs for new large optical equipments by domestic research institutions. Additionally, the geographical location of the Qinghai-Tibet Plateau fills a significant gap in the geographical longitude distribution of international quality sites, presenting major opportunities for time-domain scientific research and international cooperation. This paper summarizes the experiences and main scientific results of the Lenghu site selection and construction, and introduces the optical telescope projects that have been operational and signed at Lenghu.