What does the propagation phase shift depend on?

The propagation phase shift is indeed dependent on the size of the scatterer. When radar waves interact with a scatterer, such as precipitation particles or other atmospheric phenomena, the size of the scatterer affects how the radar waves are scattered. Larger scatterers create a more significant phase change in the radar return signal compared to smaller scatterers. This is because the radar wavelengths can be affected by diffraction and reflection processes differently based on the physical dimensions of the particles.

For instance, in weather radar applications, precipitation particles that are larger, such as hail or heavy raindrops, will produce a more pronounced phase shift compared to smaller particles like mist or light rain. This relationship between the scatterer's size and the resulting phase shift is crucial for interpreting radar data, estimating precipitation intensity, and identifying different types of precipitation in meteorological studies.

While atmospheric pressure, wind direction, and temperature gradients can influence various aspects of radar operation and signal propagation, they do not directly affect the immediate phase shift caused by scattering. Thus, it's the size of the scatterer that is the primary factor determining the propagation phase shift in radar meteorology.