What effect does increasing the area have on intensity for a perfectly efficient radar?

When considering the relationship between area and intensity for a perfectly efficient radar, it is important to understand how radar systems work and how target detection is affected by these parameters.

The intensity of radar, typically measured in terms of power per unit area (often referred to as the radar signal's energy density), is inversely related to the area being illuminated. As the area increases, the same amount of transmitted power is spread over a larger surface, resulting in a lower intensity of the radar signal. This phenomenon can be explained by the inverse square law, which states that the intensity of a signal decreases with the square of the distance from the source; when you increase the area, you effectively dilute the radar signal across a broader area, leading to lower intensity per unit area.

Thus, for a perfectly efficient radar, as the area being observed increases without a corresponding increase in transmitted power, the intensity diminishes. Consequently, when the area increases, the intensity decreases, which aligns with the correct answer of decreasing intensity. This understanding is crucial in radar meteorology as it relates to target detection capabilities and the effectiveness of radar systems in various environments.