Note4Students
From UPSC perspective, the following things are important :
Prelims level: Doppler, X-Band Radar, NISAR
Why in the News?
After the floods and landslides in Wayanad in July 2024, the Union Ministry of Earth Sciences approved the installation of an “X-band radar” in the district.
What is an X-Band Radar?
- An X-band radar is a type of radar that operates in the 8-12 GHz frequency range of the electromagnetic spectrum, with wavelengths of 2-4 cm.
- This radar is particularly useful for detecting smaller particles like raindrops, fog, and other fine materials due to its shorter wavelengths, which allow for higher resolution images.
Key Features of X-Band Radar:
- High Resolution: The shorter wavelength provides more detailed images, making it ideal for tracking weather phenomena, including precipitation and particle movements.
- Limited Range: They have a relatively shorter range compared to other types like S-band radars because higher frequency signals get attenuated (weakened) faster as they travel through the atmosphere.
Applications: In weather forecasting, X-band radars are used for short-range weather monitoring, such as predicting rainfall intensity and landslides. They are also used in air traffic control and military applications. |
What is a Doppler Radar?
- A Doppler radar is a type of radar used primarily in meteorology to measure the velocity and movement of weather formations, such as clouds and storms.
- It works on the principle of the Doppler effect, which refers to the change in frequency of waves as their source moves relative to the observer.
It’s applications:
- Velocity Measurement: By measuring these changes in frequency, Doppler radar can determine how fast the object (e.g., rain cloud) is moving and in which direction.
- Weather Monitoring: Doppler radar helps in tracking rainfall intensity, detecting wind patterns, and predicting the formation of storms or tornadoes.
India’s Radar Network
- The India Meteorological Department (IMD) began using radars in weather applications in the 1950s.
- The first indigenously designed X-band storm detection radar was installed in 1970 in New Delhi.
- In 1996, the IMD replaced 10 outdated X-band radars with digital X-band radars.
- India’s radar network includes both wind-finding and storm-detecting X-band radars. The country also uses S-band radars (2-4 GHz) for long-range detection. The first S-band cyclone detection radar was installed in Visakhapatnam in 1970.
Recent Developments:
- In September 2024, the Ministry of Earth Sciences announced that India would install 56 additional Doppler radars over the next few years.
- On September 11, 2024, the Union Cabinet approved the ₹2,000-crore ‘Mission Mausam’, which aims to upgrade meteorological infrastructure, including the installation of up to 60 radars by 2026.
- The Wayanad radar initiative also includes the installation of a C-band radar (4-8 GHz) in Mangaluru, with an observational range of 250 km.
About the NISAR
- NISAR, short for NASA-ISRO Synthetic Aperture Radar, is a joint satellite mission being developed by NASA and ISRO.
- NISAR will use radar imaging to create a high-resolution map of the earth’s landmasses, tracking changes in natural processes.
- Its payload consists of an L-band radar (1.25 GHz, 24 cm) built by NASA and an S-band radar (3.2 GHz, 9.3 cm) built by ISRO.
- NISAR is expected to launch in 2025 aboard an ISRO GSLV Mk II rocket, with a total cost of $1.5 billion, primarily funded by NASA.
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PYQ:
[2016] Discuss India’s achievements in the field of Space Science and Technology. How the application of this technology has helped India in its socio-economic development? |
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