Electromagnetic Spectrum and Atmospheric Windows MCQ with answer and solution

Concept

Spectral signature concept and reflectance curves

Formula

ρ(λ) = E_r(λ) / E_i(λ)

Step-by-step solution

1. Every earth surface material absorbs, reflects, and transmits electromagnetic radiation characteristically at specific wavelengths. 2. Plotting percentage reflectance against wavelength yields a distinctive curve called the spectral signature. 3. Therefore, option A accurately defines spectral signature. Answer: A

Explanation

In remote sensing, a spectral signature refers to the unique and characteristic variation of electromagnetic reflectance or emittance of an object across different wavelengths. Different materials such as healthy green vegetation, clear water, and dry soil exhibit distinctive spectral response curves that enable their identification and classification. Thus, option A is correct.

Why the other options are wrong

B) Spatial pattern in panchromatic images represents geometric texture, not spectral signature. C) Time interval between satellite passes defines temporal resolution. D) Curvature effects cause geometric distortion, not spectral signatures.

Shortcut

Spectral signature = Optical fingerprint of a material across wavelengths.

Common mistake

Confusing spectral signature with spatial pattern, temporal revisit interval, or radiometric resolution.