Microwave radar signatures of precipitation from S band to Ka band: application to GPM mission

Radars at different frequencies have been used over five decades for observing precipitation. S and C bands have been employed for long range coverage observations. Dual-polarization X-band radars have been shown to be useful for networked applications. Space borne precipitation radars have been at Ku band, or higher frequencies such as Ka, as in the GPM mission. This paper presents a comprehensive and unified view of radar precipitation observations at these bands, highlighting the advantages, limitations and the specific applications associated to them. Moreover, relationships between radar measurements at different bands in rain are illustrated. Examples of their use to predict attenuation margin and to simulate observations of the dual polarization, dual frequency Ku and Ka scanning radar D3R to be used in the ground validation program of the GPM mission are shown.