Question

UPSC Prelims 2019 Question:

For the measurement/ estimation of which of the following are satellite images/remote sensing data used?

  1. Chlorophyll content in the vegetation of a specific location 
  2. Greenhouse gas emissions from rice paddies of a specific location 
  3. Land surface temperatures of a specific location

Select the correct answer using the code given below.

  1. 1. 1 only
  2. 2. 2 and 3 only
  3. 3. 3 only
  4. 4. 1, 2 and 3

Answer (Detailed Solution Below)

Option 4: 1, 2 and 3

Detailed Solution

Explanation: 

  • Remote sensing is the process of detecting and monitoring the physical characteristics of an area by measuring its reflected and emitted radiation at a distance (typically from satellite or aircraft). Special cameras collect remotely sensed images, which help researchers "sense" things about the Earth. The various applications of these remote sensing are as follows:

Field/Sector

Applications

Agriculture

    • To determine soil moisture and soil types for precision farming
    • To calculate Chlorophyll content in the vegetation of a specific location
  • To estimate surface temperatures of land of a specific location 

So, points 1 and 3 are correct.

Environment

  • To calculate Greenhouse gas emissions from rice paddies of a specific region. So, point 2 is correct.
  • To measure the depth of snowpack like Arctic, Antarctic for climate change perspective
  • To study glacier melts and effects on sea levels
  • To keep eye on different species of flora and fauna (Fight for illegal activities and against forest fire) 

Disaster Management

  • To Monitor active volcanoes using thermal remote sensing
  • To map potential landslides with interferometry
  • To Quantify the damage after an earthquake
  • To Track various hazards for better response and recovery

Hydrology

  • To delineate watershed areas by providing accurate elevation data
  • To Locate groundwater activity for wells

Defence

  • To spy on enemies with reconnaissance satellites
  • For searching for aircrafts and saving lives after fatal crashes
  • For Navigating ships safely with the most optimal route

Mining

  • Extracting mineral deposits with hyperspectral remote sensing
  • Studying geology of the Earth’s surface

Oceanography

  • Detecting oil spills for marine life and environmental preservation
  • Watching algae grow as an indicator of environmental health

Therefore, option (4) is the correct answer.

Subject: Science & Technology | Space and Related Developments

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