Monday, 19 December 2016

Things You Need To Know About Indian Remote Sensing Satellites - ISRO

In a more restricted sense, 'remote sensing' usually refers to the technology of acquiring information about the earth's surface (land and ocean) and atmosphere using sensors on-board airborne (aircraft, balloons) or space-borne (satellites, space shuttles) platforms.

Remote Sensing is a process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance from the targeted area. Special cameras collect remotely sensed images of the Earth, which help us "sense" things about the Earth. It is also defined as the collection of information about an object/ phenomenon without making physical contact with the object.

Satellites can be classified by their functions. Satellites are launched into space to do a specific job. The type of satellite that is launched to monitor cloud patterns for a weather station will be different than a satellite launched to send television signal. The satellite must be designed specifically to fulfil its function.

Below are the names of nine different types of satellites. They are;
  1. Astronomy satellites (eg: Hubble Space Telescope)
  2. Atmospheric Studies satellites (eg: Polar)
  3. Communications satellites (eg: Anik E)
  4. Navigation satellites (eg: Navstar)
  5. Reconnaissance satellites (eg: Kennan, Big Bird, Lacrosse)
  6. Remote Sensing satellites (eg: Radarsat)
  7. Search and Rescue satellites (eg: Cospas-Sarsat)
  8. Space Exploration satellites (eg: Galileo)
  9. Weather satellites (eg: Meteosat)
In current usage, the term "remote sensing" generally refers to the use of satellite- or aircraft-based sensor technologies to detect and classify objects on Earth, including on the surface and in the atmosphere and oceans.

It may be split into-

Active remote sensing- When a signal is emitted by a satellite or aircraft and its reflection by the object is detected by the sensor.

Passive remote sensing- When the reflection of sunlight is detected by the sensor.


Natural resource management is a broad field covering many different application areas as diverse as monitoring fish stocks to effects of natural disasters (hazard assessment).

Remote sensing can be used for applications in several different areas, including:
  • Mineral exploration
  • Geography and most Earth Science disciplines (for example, hydrology, ecology, glaciology, geology)
  • Hazard assessment
  • Oceanography
  • Agriculture and forestry
  • Land degradation
  • Environmental monitoring
It also has military, intelligence, commercial, economic, planning, and humanitarian applications. Some applications only require seasonal imaging (crop identification, forest insect infestation, and wetland monitoring), and some need imaging only once (geology structural mapping).

Each application itself has specific demands, for spectral resolution, spatial resolution, and temporal resolution. For a brief, spectral resolution refers to the width or range of each spectral band being recorded. Temporal resolution refers to the time interval between images. There are applications requiring data repeatedly and often, such as oil spill, forest fire, and sea ice motion monitoring.

After the success of Bhaskara, many IRS have been launched. With different variants like A, B, C, D of IRS, 1 to 7 of IRS-P, Oceansat etc. Recently on 7 December 2016, another remote sensing satellite was launched by Indian Space Research Organisation (ISRO).

This is one of the biggest factor responsible for our nation's growth as we need not rely upon foreign countries.

Written by Pragati Jain
Grew up in Indore, M.P. I am pursuing B.E. in Electronics and Communication from Medi-Caps Indore. I love writing, sports and playing piano.

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