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Successful Launch of Earth-Observation Satellite RISAT-2B
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- Achievements of Indians in science & technology; indigenization of technology and developing new technology.
In News: India’s Polar Satellite Launch Vehicle (PSLV-C46) successfully launched RISAT-2B satellite
RISAT-2B is radar imaging earth observation satellite weighing about 615 kg; the all-weather imaging satellite that boosts the capability to image earth resources as well as enhance surveillance and security.
Utility for India
The satellite is intended to provide services in the field of Agriculture, Forestry and Disaster Management. The RISAT, or radar imaging satellite, is equipped with a sensor known as ‘synthetic aperture radar’ that takes what are known as ‘radar images’. Globally, security agencies use the images and services of such satellites.
The radar imaging satellite can observe and image the earth from about 500 km. It is an improvement over the remote sensing satellites in natural resources observation and management.
The biggest advantage is that ground imageries can be collected during rains and despite dust, clouds or darkness and during all seasons, thus ensuring continuous and reliable data.
Explained
- Very much like the flashlights of the camera, which release visible light to illuminate an object and then use the reflected light to create an image, the synthetic aperture radar send out hundreds of radio signals every second towards the subject (in this case, the earth) and capture the reflected signals to create a radio image, which can then be used by computers to build a real image.
- Because the very large wavelength radio waves are not obstructed by clouds, dust or similar other obstacles in the atmosphere, they produce reliable images during day and night and all seasons.
- The X-band synthetic aperture radar can also provide added details such as size of objects on earth, structures, movement and change, which complements the data that is being gathered through the normal optical remote-sensing satellites.
Connecting the Dots :
- ISRO’s RISAT-2B satellite works like a camera flash. Explain the mechanism.