What describes how large a scatterer appears to a radar?

The backscattering cross section is a critical parameter in radar meteorology that quantifies how effectively a target, or scatterer, returns radar energy back to the radar system. It represents the effective area that a scatterer presents to an incoming radar wave, providing a measure of the strength of the signal that is reflected back to the radar.

When the backscattering cross section is large, it indicates that the scatterer can reflect a significant amount of the radar signal, making it appear larger and more detectable by the radar. This is particularly relevant in meteorology for understanding precipitation, where raindrops, snowflakes, and other particles scatter radar waves differently, leading to variations in the observed intensity of the radar returns.

Radial velocity, signal-to-noise ratio, and frequency spectrum all pertain to different aspects of radar measurements, such as the speed of moving targets, the clarity of the received signal compared to background noise, and the analysis of the frequencies within the radar signal, respectively. However, they do not directly describe the apparent size of a scatterer as it relates to radar observations in the way that the backscattering cross section does.