Question

Choose the CORRECT statement regarding microwave remote sensing

• A. \( \text{Spatial resolution of passive microwave remote sensor is coarser than that of active microwave remote sensor from the same platform} \)
• B. \( \text{The intensity of signal returned by an object does not depends on its geometric as well as dielectric properties} \)
• C. \( \text{It is possible to "see through" the dense forest canopy using X-band active microwave remote sensing (i.e., signals can penetrate the dense forest canopy)} \)
• D. \( \text{Microwave remote sensing cannot be used in soil moisture studies} \)

Hint:

Remember that active microwave sensors have more control over the signal, often leading to better resolution.

Answer 1

The Correct Option is A

\begin{itemize} \item (A) Spatial resolution of passive microwave remote sensor is coarser than that of active microwave remote sensor from the same platform: This is generally correct. Active microwave sensors (like radar) can achieve finer spatial resolutions compared to passive microwave radiometers operating from the same platform due to their ability to control the emitted energy and use techniques like synthetic aperture radar (SAR). \item (B) The intensity of signal returned by an object does not depend on its geometric as well as dielectric properties: This is incorrect. The backscattered microwave signal is strongly influenced by both the geometric (shape, surface roughness) and dielectric (electrical properties) of the object. \item (C) It is possible to "see through" the dense forest canopy using X-band active microwave remote sensing (i.e., signals can penetrate the dense forest canopy): While microwaves can penetrate vegetation to some extent, X-band frequencies have limited penetration capability in dense forest canopies. Longer wavelengths (like L-band and P-band) are more effective for penetrating vegetation. \item (D) Microwave remote sensing cannot be used in soil moisture studies: This is incorrect. Microwave remote sensing is highly sensitive to the dielectric properties of soil, which are strongly related to soil moisture content. It is a valuable tool for soil moisture estimation. \end{itemize}