Tiananmen Square is covered in haze from a Beijing sandstorm in 2017. The sandstorm affected much of north China, including Beijing, with the capital's meteorological center issuing a blue alert Thursday morning. Photo: IC

China's domestically developed smog-monitoring laser radar system has been deployed in many places to monitor air quality. 

The Hefei Institute of Physical Science of Chinese Academy of Sciences system passed inspection by the Ministry of Science and Technology, the Xinhua News Agency said on Friday. 

The system can monitor smog distribution within 10 kilometers and analyze its composition, said the report. 

"Accurately knowing the composition of the smog, where it comes from and where it goes will help analyze the causes of pollution and precisely formulate strategies to fight air pollution," Zhang Tianshu, a project executive, told Xinhua.

The achievement broke the monopoly of core laser radar technologies held by developed countries, said the report. 

The system has already been put in use to monitor smog in densely-populated areas including the Yangtze River Delta, Pearl River Delta, Southwest China's Sichuan Province and Chongqing Municipality, it said.

Wang Gengchen, a research fellow at the Atmospheric Physics Institute of Chinese Academy of Sciences, told the Global Times on Sunday that laser radar excels at automated, real-time monitoring. 

But data gathered by laser radar can also generate errors through indirect calculation and thus the system cannot replace traditional measurements, Wang said.  

Physical measurements that analyze air quality require sampling and weighing in labs that makes it hard to achieve real-time monitoring, said Wang, adding optical measurement cannot usually be carried out on a mass scale as it probes with a beam of light.