Why in the news?

  • The Government of India informed Parliament that 47 Doppler Weather Radars (DWRs) are currently operational across the country, covering about 87% of India’s geographical area.

Doppler Weather Radar (DWR)

  • What is it?: A Doppler Weather Radar (DWR) is a sophisticated remote sensing instrument used to track weather by sending out radio waves and analyzing how they bounce off particles like rain, snow, or hail.
  • Basic Principle: The DWR operates based on the Doppler Effect.
  • How does it work?
    • Detect precipitation (rain, snow, hail)
    • Track the movement of clouds and storms
    • Estimate rainfall intensity
    • Provide short-term forecasts (nowcasting) for extreme weather events
Doppler Effect

  • The Doppler effect describes the change in frequency or wavelength of a wave in relation to an observer moving relative to the wave source. Waves compress to a higher frequency when the source approaches and stretch to a lower frequency when it recedes. Named after Christian Doppler, who described it in 1842, this phenomenon applies to sound, light, and radio waves.

Source: Indian Express