Topic Of The Day:-“Eye In The Sky: On RISAT-2B”
RISAT-2B Will Enhance India’s Monitoring Capabilities For Civil And Military Purposes
With the successful pre-dawn launch of RISAT-2B satellite on May 22, the Indian Space Research Organisation (ISRO) has added another feather to its cap. The satellite will enhance India’s capability in crop monitoring during the monsoon season, forestry mapping for forest fires and deforestation, and flood mapping as part of the national disaster management programme. Given that overcast skies are a constant during the monsoon season and during times of flood, the ability to penetrate the cloud cover is essential. While optical remote sensing that relies on visible light for imaging gets obstructed by clouds, RISAT-2B will not. Much like the RISAT-1 satellite that was launched by ISRO in April 2012, RISAT-2B will also use microwave radiation. Unlike visible light, microwaves have longer wavelength and so will not be susceptible to atmospheric scattering. Microwave radiation can thus easily pass through the cloud cover, haze and dust, and image the ground. Hence, RISAT-2B satellite will be able to image under almost all weather and environmental conditions. Since it does not rely on visible light for imaging, it will be able to image the ground during both day and night. The satellite does not have passive microwave sensors that detect the radiation naturally emitted by the atmosphere or reflected by objects on the ground. Instead, RISAT-2B will be transmitting hundreds of microwave pulses each second towards the ground and receiving the signals reflected by the objects using radar. The moisture and texture of the object will determine the strength of the microwave signal that gets reflected. While the strength of the reflected signal will help determine different targets, the time between the transmitted and reflected signals will help determine the distance to the object.
The RISAT-2B satellite uses X-band synthetic aperture radar for the first time; the synthetic aperture radar was developed indigenously. Unlike the C-band that was used by RISAT-1, the shorter wavelength of the X-band allows for higher resolution imagery for target identification and discrimination. Since it has high resolution, the satellite will be able to detect objects with dimensions of as little as a metre. This capacity to study small objects and also movement could be useful for surveillance. As K. Sivan, ISRO Chairman and Secretary, Department of Space, had said last month, the satellite could be used for civil and strategic purposes. RISAT-2B will have an inclined orbit of 37 degrees, which will allow more frequent observations over the Indian subcontinent. With ISRO planning to launch four more such radar imaging satellites in a year, its ability to monitor crops and floods as well as engage in military surveillance will be greatly enhanced.
MEANINGS AND WORDS
- pre-dawn
Meaning: relating to or taking place before dawn.
Example Sentence: “in a predawn raid, troops stormed the university campus”
- enhance
Meaning: intensify, increase, or further improve the quality, value, or extent of.
Synonyms: Increase, add to, intensify, magnify
Antonyms: diminish, mar
Example Sentence: “his refusal does nothing to enhance his reputation”
- capability
Meaning: the power or ability to do something.
Synonyms: Ability, capacity, power, potential, potentiality
Antonyms:Iinability, incompetence
Example Sentence: “he had an intuitive capability of bringing the best out in people”
- deforestation
Meaning: the action of clearing a wide area of trees.
Synonyms: desertification , erosion , logging
Antonyms: Afforestation
Example Sentence: “a key aim is to try to halt widespread deforestation in the Amazon”
- disaster
Meaning: a sudden accident or a natural catastrophe that causes great damage or loss of life.
Synonyms: Catastrophe, calamity, cataclysm, tragedy, act of God
Antonyms: Blessing
Example Sentence: “159 people died in the disaster”
- overcast
Meaning: (of the sky or weather) marked by a covering of grey cloud; dull.
Synonyms: Cloudy, clouded, clouded over, overclouded, sunless
Antonyms: bright, clear
Example Sentence: “a chilly, overcast day”
- penetrate
Meaning: go into or through (something), especially with force or effort.
Synonyms: Pierce, puncture, make a hole in, perforate
Antonyms: Surrender, Retreat
Example Sentence: “the shrapnel had penetrated his head”
- obstructed
Meaning: block (an opening, path, road, etc.); be or get in the way of.
Synonyms: block, block up, clog, clog up, get/stand in the way of
Antonyms: clear
Example Sentence: “she was obstructing the entrance”
- scattering
Meaning: an act of scattering something.
Synonyms: Handful, few, one or two, not many, a small number
Example Sentence: “the colossal wastage involved in a random scattering”
- emitted
Meaning: produce and discharge (something, especially gas or radiation).
Synonyms: discharge, release, give out/off, pour out, send forth
Antonyms: absorb
Example Sentence: “even the best cars emit carbon dioxide”
- transmitting
Meaning: cause (something) to pass on from one person or place to another.
Synonyms: Transfer, pass on, hand on, communicate, convey
Antonyms: receive
Example Sentence: “knowledge is transmitted from teacher to pupil”
- aperture
Meaning: an opening, hole, or gap / a space through which light passes in an optical or photographic instrument, especially the variable opening by which light enters a camera.
Synonyms: opening, hole, gap, space, slit, slot, vent, passage
Antonyms: Agreement, Cut, Break
Example Sentence: “the bell ropes passed through apertures in the ceiling”
- indigenously
Meaning: originating or occurring naturally in a particular place; native.
Synonyms: Native, aboriginal, local;
Antonyms: Expatriate, migrant, adventitious
Example Sentence: “the indigenous peoples of Siberia”
- discrimination
Meaning: the unjust or prejudicial treatment of different categories of people, especially on the grounds of race, age, or sex.
Synonyms: prejudice, bias, bigotry, intolerance, narrow-mindedness
Antonyms: Impartiality
Example Sentence: “victims of racial discrimination”
- detect
Meaning: discover or identify the presence or existence of.
Synonyms: notice, become aware of, perceive, note, discern
Antonyms: Conceal, Ignore
Example Sentence: “cancer may soon be detected in its earliest stages”
- inclined
Meaning: leaning or turning away from the vertical or horizontal; sloping.
Synonyms: Disposed, minded, of a mind, willing
Antonyms: Disinclined
Example Sentence: “an inclined ramp”
- observations
Meaning: the action or process of closely observing or monitoring something or someone.
Synonyms: watching, monitoring, scrutiny, examination, inspection
Antonyms: Disbelief, Neglect, Unobservance
Example Sentence: “she was brought into hospital for observation”
- engage
Meaning: occupy or attract (someone’s interest or attention).
Synonyms: capture, catch, arrest, grab, seize, draw
Antonyms: Lose
Example Sentence: “he ploughed on, trying to outline his plans and engage Sutton’s attention”
- surveillance
Meaning: close observation, especially of a suspected spy or criminal.
Synonyms: observation, scrutiny, watch, view, inspection
Antonyms: Neglect, Indifference
Example Sentence: “he found himself put under surveillance by British military intelligence”
- enhanced
Meaning: intensify, increase, or further improve the quality, value, or extent of.
Synonyms: Increase, add to, intensify, magnify, amplify, inflate, strengthen
Antonyms: diminish, mar
Example Sentence: “his refusal does nothing to enhance his reputation”
