ONE CONDITION OF USE OF THE WEATHER RADAR EQUATION

B. S. Yurchak

One of the possible causes of observed divergences between the results of comparative measurements of cloud and rain microstructure with contact sensors and retrieved from radar reflectivity factor Z is considered. The condition under which the average power of an echo signal reflected by an extended meteorological target can be calculated as a sum of powers of the elementary echo signals reflected by single particles of this target and the concept of Z can be applied is analyzed. It is shown that the average power of an echo signal is proportional to Z, i.e., to the sixth moment of the spectrum of drops, only in the case of Poisson fluctuations of concentration on the scales much smaller than radar wavelength.