X-BAND RADAR
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- Radar, an abbreviation for ‘radio detection and ranging,’ uses radio waves to measure the distance, speed, and physical properties of objects nearby. The device’s transmitter sends out a signal directed at an object (in meteorology, for instance, a cloud), and a portion of the signal is reflected back to the radar, where a receiver captures and analyzes it.
- A well-known application of this technology is weather radar, often referred to as Doppler radar. The Doppler effect describes the shift in wave frequency as the source moves relative to an observer. In meteorology, Doppler radars can determine a cloud's speed and direction by analyzing how its movement alters the frequency of the returning radiation.
- Pulse-Doppler radars, which emit radiation in pulses, can assess the intensity of phenomena like rainfall by measuring the rate at which the pulses are reflected back.
- Through this process, modern Doppler radars are capable of monitoring weather conditions and predicting wind patterns, storm development, and more
- Doppler radar operates based on Rayleigh scattering, which occurs when the object scattering the radiation is much smaller than the wavelength. To detect smaller particles like raindrops or fog, the radar must use shorter wavelengths, such as those in the X-band.
- X-band radar emits radiation in the X-band of the electromagnetic spectrum, which ranges from 8-12 GHz and corresponds to wavelengths of about 2-4 cm, located in the microwave region.
- These shorter wavelengths enable the radar to generate higher-resolution images, but higher frequency radiation is attenuated more quickly, giving X-band radars a relatively limited range.
- In Wayanad, the new radar will track the movement of small particles, such as soil, to help issue landslide warnings.
- It will also conduct high temporal sampling, meaning it will rapidly scan the environment to detect particle movements over shorter time intervals
- The India Meteorological Department (IMD) began utilizing radar for weather monitoring in the early 1950s. In 1970, New Delhi saw the installation of the first domestically designed and built X-band storm detection radar. By 1996, IMD replaced 10 outdated X-band radars with modern digital versions.
- India’s radar network includes both wind-finding and storm-detecting X-band radars, with some systems offering dual capabilities. Additionally, the country employs S-band radars (2-4 GHz) for long-range detection.
- The first S-band radar for cyclone detection was installed in Visakhapatnam in 1970, while the first domestically produced S-band radar was commissioned in Mumbai in 1980.
- In September 2024, the Ministry of Earth Sciences announced plans to add 56 more Doppler radars in the coming years. On September 11, the Union Cabinet approved the ₹2,000-crore 'Mission Mausam' to enhance the country’s meteorological infrastructure, which includes the installation of up to 60 new radars by 2026 as part of the first phase.
- In August, Minister of State for Earth Sciences Jitendra Pradhan informed Parliament that the government has initiated the procurement and installation of 10 X-band Doppler radars to improve weather forecasting in northeastern states and the Lahaul and Spiti district of Himachal Pradesh.
- The installation of an X-band radar in Wayanad is part of a larger effort that also included setting up a C-band radar (4-8 GHz) with a 250 km observation range in Mangaluru
NISAR (NASA-ISRO Synthetic Aperture Radar) is a joint Earth observation satellite mission developed by NASA and the Indian Space Research Organisation (ISRO). It is designed to provide detailed, high-resolution data on Earth's surface to help monitor global environmental changes, natural disasters, and the effects of climate change.
Key details about NISAR include:
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Purpose: NISAR will use advanced radar imaging techniques to measure subtle changes in the Earth’s surface. It will be especially useful in tracking movements caused by earthquakes, volcanic eruptions, landslides, and other natural hazards. Additionally, NISAR will monitor changes in ice sheets, glaciers, forests, and agricultural lands to better understand ecosystem dynamics and climate impacts.
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Technology: The satellite is equipped with dual-frequency radar systems—L-band (operated by NASA) and S-band (operated by ISRO)—to penetrate through clouds and vegetation and capture high-resolution images day and night, regardless of weather conditions.
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Applications: NISAR will have wide-ranging applications in areas such as disaster management, resource management, urban planning, agriculture, and forestry. The data will help researchers better understand phenomena like tectonic movements, glacier retreat, and biomass measurement.
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Launch: The satellite is expected to launch in 2024, aboard an Indian launch vehicle (GSLV) from ISRO’s Sriharikota launch site in India
Mission Mausam is an initiative launched by the Government of India, specifically led by the Ministry of Culture, with the aim of promoting cultural and historical connections across the Indian Ocean region. It focuses on the maritime history of India and its neighboring countries, highlighting the shared heritage and links between these regions, which were established through ancient maritime routes.
Key objectives and features of Mission Mausam include:
- The mission seeks to revive and strengthen the cultural, economic, and historical ties among nations in the Indian Ocean, including South Asia, Southeast Asia, the Middle East, and East Africa. These regions were connected by ancient maritime trade routes, sometimes referred to as the "Monsoon Trade Route."
- Mission Mausam focuses on studying and documenting the shared maritime history of these regions. This includes understanding the role of monsoons in facilitating maritime trade and cultural exchanges, as well as exploring the impact of such exchanges on art, architecture, and cultural practices
- The initiative encourages collaboration between countries in the Indian Ocean region through joint research, heritage conservation projects, and cultural exchange programs. It aims to create a shared narrative that recognizes the interconnectedness of these regions in shaping history.
- A significant component of the mission is to nominate certain transnational sites and cultural landscapes in the Indian Ocean for UNESCO World Heritage status. These could include important historical ports, trading centers, and sites that reflect the cultural exchange facilitated by maritime trade
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For Prelims: PSLV, GSLV, GSLV Mk-III, SSLV
For Mains: GS III- Science & Technology- Satellite Applications, Challenges and Solutions
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Previous Year Questions
1. With reference to India's satellite launch vehicles, consider the following statements: (UPSC 2018)
1. PSLVs launch satellites useful for Earth resources monitoring whereas GSLVs are designed mainly to launch communication satellites.
2. Satellites launched by PSLV appear to remain permanently fixed in the same position in the sky, as viewed from a particular location on Earth.
3. GSLV Mk III is a four- staged launch vehicle with the first and third stages using solid rocket motors; and the second and fourth stages using liquid rocket engines.
Which of the statements given above is/are correct?
A. 1 only
B. 2 and 3
C. 1 and 2
D. 3 only
Answer: A
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