New ‘Doppler radar’ to be installed in Maharashtra
In the year 2021, the India Meteorological Department (IMD) will install seven new Doppler radars in Maharashtra.
It is to be known that the ‘Union Ministry of Earth Sciences’ had commissioned an ‘X-band Doppler Weather Radar’ (DWR) in January this year to closely monitor the weather changes over the Himalayas.
It may be noted that the ‘X-band Doppler Weather Radar’ has been indigenously manufactured in India. 10 such radars have been manufactured in India. Out of which two radars have already been installed for the study of Himalayas.
- Doppler radars with varying frequencies such as S-band, C-band and X-band are often used by IMD to study and track the movement of weather systems, cloud bands and gauge rainfall over an area of about 500
- Similarly, now four X-band and one C-band radar will be installed in Mumbai, Maharashtra. In addition, a new C-band will be set up at Ratnagiri and an X-band at Vengurla. All these radars will work for multiple purposes.
Radars currently installed:
On the East Coast of India: Kolkata, Paradip, Gopalpur, Visakhapatnam, Machilipatnam, Sriharikota, Karaikal and Chennai.
West Coast: Thiruvananthapuram, Kochi, Goa and Mumbai.
Other radars: Srinagar, Patiala, Kufri, Delhi, Mukteshwar, Jaipur, Bhuj, Lucknow, Patna, Mohanbar, Agartala, Sohra, Bhopal, Hyderabad and Nagpur.
Importance of Radar:
These radars will guide meteorologists during complex weather events such as cyclones and heavy rainfall. Since radar observations will be updated every ten minutes, forecasters will be able to track the evolution of weather systems as well as their varying intensities and then predict weather events and their impact.
India Meteorological Department (IMD):
The India Meteorological Department was established in the year 1875. It is an institution of the Ministry of Earth Sciences, Government of India. It is the premier organization dealing with meteorological information, weather forecasting and seismology.
Radar (Radio Detection and Ranging):
Radar is an instrument that uses electromagnetic waves in a microwave field to detect speed and direction, height and intensity, movement of moving and stationary objects.
It is a special radar that uses the Doppler effect to collect data related to the velocity of objects located at some distance from each other.
What is Doppler Effect?
- As a result of the relative motion between a wave source and the observer, the frequency of the wave appears to have changed. This apparent change in the frequency of a wave is called the “Doppler effect” or Doppler shift.
- It targets a desired object with a microwave signal and analyzes how the motion of the target object has changed the frequency of the returned signals. This variation gives a direct and highly accurate measurement of the radial component of the target’s velocity relative to the ‘radar’.
Doppler Weather Radar (DWR):
- Designed to improve the accuracy of weather forecasting and monitoring by placing a ‘Parabolic Dish Antenna’ and a Foam Sandwich Spherical Radome in the ‘Radar’ using the Doppler principle is.
- DWRs are equipped with instruments to measure rainfall intensity, wind gradient and velocity, which provide information about the center of the cyclone and the direction of the dust tornado.
Doppler Radar Types:
Doppler radar is divided into different categories on the basis of wavelength, such as- L, S, C, X, K radar.
X-band radar: 2.5 to 4 cm. It operates at a wavelength of 8 to 12 GHz. Due to such a short wavelength, X-band radars are very sensitive to be able to detect fine particles.
It is used for information about storms and lightning.
C-band radar: These radars operate at a wavelength of 4 to 8 cm and a frequency of 4 to 8 GHz. Due to the wavelength and frequency, the size of the dish does not need to be very large.
Signals are more easily attenuated in this, so the use of this type of radar is best suited for short distance weather observation. This radar is used as guidance at the time of cyclone tracking.
S-band radar: It operates at a wavelength of 8 to 15 cm and a frequency of 2 to 4 GHz. S-band radars are not easily attenuated due to wavelength and frequency. Due to this feature, it is useful for observing near and distant weather.
Source – Indian Express