UPSC CSE Prelims
Question 52
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.
View correct answer and explanation
Correct answer: D
Correct Option: D
Explanation:
Satellite remote sensing uses vegetation spectral responses to estimate chlorophyll and thermal bands to measure surface temperature; satellite and ground-data models can also estimate rice-paddy greenhouse gas emissions.
Statement / Pair Analysis:
1 (Correct): Multispectral indices and reflectance features correlate with leaf chlorophyll content.
2 (Correct): Satellite observations combined with models can estimate methane or other GHG fluxes from rice cultivation.
3 (Correct): Thermal infrared observations measure or infer land surface temperature.
Option-wise Analysis:
A (Incorrect): It omits true item 2 (Satellite observations combined with models can estimate methane or other GHG fluxes from rice…); omits true item 3 (Thermal infrared observations measure or infer land surface temperature).
B (Incorrect): It omits true item 1 (Multispectral indices and reflectance features correlate with leaf chlorophyll content).
C (Incorrect): It omits true item 1 (Multispectral indices and reflectance features correlate with leaf chlorophyll content); omits true item 2 (Satellite observations combined with models can estimate methane or other GHG fluxes from rice…).
D (Correct): Includes all and only the true statements/pairs.
Review Note:
Remote sensing generally estimates field-scale GHG emissions indirectly using models and other input data rather than measuring every paddy’s emissions directly.