Remote Sensing Terminology Matching

This question involves matching key remote sensing terms presented in List-I with their accurate definitions from List-II. Understanding these definitions is crucial for remote sensing principles.

Active Sensing (A)

Active sensing systems emit their own electromagnetic radiation (EMR) towards a target and then detect the energy that is reflected or scattered back. Option IV, "When the sensing device detects EMR at an object and detects the amount of that energy which is reflected back", aligns with this concept, focusing on the detection of reflected energy from the object illuminated by the sensor system.

Passive Sensing (B)

Passive sensing utilizes naturally available EMR. The sensor simply records energy that is emitted or reflected by the target and measured by the sensor. Option I, "When the sensing device detects EMR originating from another source primarily from sun", correctly describes passive sensing, highlighting its reliance on external energy sources like the sun.

Spectral (C)

The term Spectral in remote sensing refers to the way targets interact with EMR across various wavelengths. It involves analyzing the unique reflectance or emission signatures of different materials. Option II, "It is the change in reflectance or emiction [emission] of objects as a function of wavelength", accurately defines spectral characteristics.

Spatial (D)

Spatial characteristics relate to the geometric properties of features as depicted in an image. This includes the shape, size, pattern, and location of objects on the ground. Option III, "It is the arrangement of terrain features providing attributes, such as shape, size and feature", correctly describes spatial information.

Correct Terminology Match

By matching each term with its definition:

• A. Active sensing corresponds to IV.
• B. Passive sensing corresponds to I.
• C. Spectral corresponds to II.
• D. Spatial corresponds to III.

The correct combination is therefore A-IV, B-I, C-II, D-III.