UN imposes new sanctions on North Korea

•  The Central Pollution Control Board is planning to use advanced LiDAR (Light Detection and Ranging) devices to vertically monitor the air quality of Delhi-NCR.

What is LIDAR?

• LiDAR is an acronym for ‘light’ and ‘radar,’ a tool developed to detect targets and to use reflected light from objects as a kind of visual sonar.
• LiDAR uses UV light and light close to infrared on the spectrum to target certain objects and analyze their distances based on the refraction of light that is bounced back. The theory is that objects of varying shapes, sizes, densities and distances will reflect light back at different speeds and thus create a high-resolution map of the surroundings.
• LiDAR is used to create incredibly detailed maps in addition to assisting researchers in the fields of geography, archeology, geology, seismology, atmospheric sciences, laser studies, and much more.
• LIDAR projects laser beams towards the sky. Subsequently, the interplay of light with the objects falling on its path through absorption, reflection, scattering help determine the composition of particulates by studying the wavelengths.
• It becomes easier to pinpoint the source of pollutants through this technique. So far India has seven stations along its eastern and western borders under a similar project, an offshoot of the Male declaration on Control and Prevention of Air Pollution and its Likely Transboundary Effects for South Asia.
• The devices may also help determine the trajectory of the pollutants present in the upper layers of the atmosphere, which are not always possible through the conventional surface-level monitoring.
• A team of CPCB scientists have found that air-borne particles from the salt mines of Afghanistan are pushing up the levels of air pollutants, especially PM2.5, in Delhi. Winds are carrying the salt particles from those areas of Afghanistan which have large salt pans.

By: Vishal