Advances in Radar Meteorology

TLDR: In this paper, the authors summarize significant developments in radar meteorology since 1958 and integrate them properly within the framework of knowledge existing prior to that time, and the emphasis in this chapter is on the basic principles and concepts of radar meteorologists.

Abstract: Publisher Summary In this chapter there were two main objectives: To summarize significant developments in radar meteorology since 1958 and to integrate them properly within the framework of knowledge existing prior to that time. The emphasis in this chapter is on the basic principles and concepts of radar meteorology. In order to relate the measured reflectivity to the size and concentration of the particles in the scattering volume, and thus to the conventional meteorological parameters, such as liquid water content and precipitation rate, this chapter is first to determine the radar cross section of an individual scatterer as a function of its refractive index, size, shape, and orientation. Because of the importance of precipitation rate in a variety of meteorological problems, ranging from flood warning to research on the water budget of a storm, extensive consideration is given to its measurement by radar. Radar measurements of storm structure and dimensions suffer from beam width and side lobe effects. In particular, the problem of estimating true storm height is discussed in some detail in the next section, and it is shown how the heights of intense storms may be greatly overestimated by the effects of side lobes, while the visible tops of some weaker storms may be underestimated. The use of Doppler or coherent radar techniques permits the measurement of the velocities of the scatterers, and so, provides a vital new dimension in radar probing of the atmosphere. The basic Doppler theory and the relation of the Doppler spectrum of the scatterers to the fluctuation spectrum of echo intensity on incoherent (conventional) pulse radar are reviewed in some detail. The final section is devoted to a comprehensive review of the long-elusive phenomenon of “angel” echoes.