As long as the lidar is turned on, the distribution of pollution sources can be seen at a glance, and fixed-point three-dimensional scanning of air pollutants can be performed at any time, and regional haze control is more accurate. Recently, the Environmental Prediction and Forecasting Center of Shijiazhuang City, Hebei Province uses a vehicle-mounted laser pointer radar to accurately detect the urban air pollution status by sailing. This is the first time in Hebei Province.
"This is a vehicle-mounted lidar device." The reporter saw a parked CMB car in the courtyard of the Shijiazhuang City Environmental Prediction and Forecast Center. The staff introduced it to the reporter. . "After modification, the car is equipped with 3D visible lidar, computer and other equipment."
The staff turned on the on-board radar, and a green beam of laser pointers visible to the naked eye was emitted through the optical sunroof on the roof. After 20 seconds, the nearby computer screen began to continuously display the three-dimensional distribution of pollution from the ground to within 15 kilometers. On this map of atmospheric pollution, the atmospheric conditions are displayed in different colors such as blue, green, yellow, and red.
"This red dot indicates that there is pollution discharge." Shi Yanshuo, an engineer at the Shijiazhuang City Environmental Forecasting and Forecasting Center, said that the relevant data detected by the radar will be sent to environmental law enforcement officers in real time, and cooperate with law enforcement officers to quickly find the source of pollution.
"Vehicle lidar has three applications, namely fixed-point vertical monitoring, fixed-point horizontal monitoring, and navigation monitoring (ie, mobile monitoring) of air quality." Shi Yanshuo said that the vertical direction can be monitored up to 25-30 kilometers; The direction can monitor within a radius of 8 kilometers, and can accurately locate latitude and longitude; using the vehicle, the laser radar can easily move everywhere and quickly find the source of pollution.
"The laser touches the particles in the atmosphere and generates an echo signal. After receiving the echo signal, the computer can form a distribution map of the pollutants in the monitored area for analysis." Shi Yanshuo said that these data were superimposed on the map, Zooming in can clearly see the specific location of the pollution source. After calculation of the correlation coefficient and formula, it can be determined whether the particulate matter in the atmosphere is PM2.5 or PM10.
The vehicle-mounted laser pointer radar uses laser to remotely detect the spatial and temporal distribution of atmospheric particulates, which can analyze the characteristics and sources of regional pollutant transport.
"For example, the monitoring data shows that the highest value between 1.5 kilometers and 3 kilometers is red, and the relative value below 1 kilometer near the ground is not high, showing yellow or orange. This shows that the pollutants are mainly concentrated In the mid- to high-altitude range, it is a source of pollution sent from outside, and the dust generated near the ground is not obvious. In this way, we can draw the conclusion that this source of pollution is dominated by external sources.