Which material is third highest reflectivity in the radar reflectivity order?

• A. Earth
• B. Wood
• C. Concrete
• D. Masonry

Answer: (C)

Radar backscatter strength depends on how well a material reflects microwaves, which is governed mainly by the material’s dielectric constant and the roughness of the surface. A higher dielectric constant and rough surface generally produce stronger backscatter.

Wood has a relatively low dielectric constant and tends to scatter less energy, so it registers weaker reflectivity.

Earth (soil) and masonry both have mineral content and moisture that raise their dielectric constant and roughness, leading to stronger backscatter. In typical radar scenarios, these two surfaces tend to produce stronger reflections than concrete.

Concrete is dense and reflective, but under common conditions its backscatter is usually somewhat less than bare earth or masonry, placing it behind those two in the reflectivity order.

So, among these materials, concrete ends up with the third-highest reflectivity.