Question

UPSC Prelims 2019 Question:

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

Chlorophyll content in the vegetation of a specific location

Greenhouse gas emissions from rice paddies of a specific location

Land surface temperatures of a specific location

Select the correct answer using the code given below.

1. 1 only
2. 2 and 3 only
3. 3 only
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

Latest UPSC Exam 2026 Updates

Last updated on Sep, 2026

→ UPSC 2027 Notification will be released on 13 January 2027 at upsconline.nic.in.

Tags: Analytical factual UPSC Prelims 2019 UPSC Prelims 2019 Question

Prafulla Vats

Prafulla Vats is an experienced SEO and content strategist with over 4 years of expertise in driving organic growth across education and service niches. He specializes in crafting data-driven content strategies that help students and professionals access accurate, well-researched information. Through his work, he focuses on improving visibility, engagement, and trust through high-quality, SEO-optimized content.