Question

List any two geometric factors which affect the interaction between microwaves and Earth's surface.

Hint:

Imagine shining a flashlight at a tilted mirror (topography) versus a bumpy wall (surface roughness). Both change how the light bounces back at you!

Answer 1

Step 1: Concept
Active microwave remote sensing (like Radar) beams energy toward the Earth and records the signal that bounces back (backscatter).

Step 2: Meaning
The physical shape and structure of the targets on the ground heavily dictate how much of that microwave energy is reflected to the sensor versus scattered away.

Step 3: Analysis

• Electrical properties (like moisture) dictate interaction but are physical, not geometric.
• Surface Roughness: A smooth geometric surface (like calm water) acts like a mirror, reflecting radar away. A rough surface scatters the radar beam in all directions.
• Topography and Orientation (Slope/Aspect): The angle at which the terrain is tilted relative to the incoming radar beam dictates the strength of the return signal.

Step 4: Conclusion
The two primary geometric factors controlling radar backscatter are surface roughness and topography. Final Answer: 1. Surface roughness, 2. Topography (Slope and Aspect)