Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R)
Assertion (A) : Operational microwave remote sensing has both active and passive sensors.
Reason (R) : Active microwave remote sensing depends on the emission characteristics of various target surfaces or the media of interest.
In light of the above statements, choose the correct answer from the options given below.
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Always associate active systems with self-generated energy (like RADAR or LIDAR).
They control their own signals and are independent of natural thermal emissions or solar illumination.
Both (A) and (R) are true and (R) is the correct explanation of (A).
Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
(A) is true but (R) is false.
(A) is false but (R) is true.
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The Correct Option isC
Solution and Explanation
Step 1: Understanding the Concept:
Remote sensing sensors are classified as either active or passive based on whether they require their own source of electromagnetic energy to illuminate targets. Step 3: Detailed Explanation:
1. Assertion (A): Microwave remote sensing utilizes both active instruments (such as RADAR and scatterometers, which emit their own microwave pulses) and passive instruments (such as microwave radiometers, which detect naturally emitted microwave energy). Thus, Assertion (A) is true.
2. Reason (R):Passive microwave remote sensing measures the naturally emitted thermal microwave radiation from target surfaces.
Conversely, Active microwave remote sensing systems provide their own illumination source by transmitting a pulse of microwave energy and measuring the backscattered echo returned from the target.
Hence, active systems do not rely on natural emission characteristics. Since the statement claims active sensing depends on emission characteristics, Reason (R) is false. Step 4: Final Answer:
The correct option is 3, which corresponds to (A) is true but (R) is false.
