Proposal for a Spaceborne Dual-Beam Rain Radar with Doppler Capability

Abstract

The potential characteristics and performances of a spaceborne dual-beam radar (or stereo radar) operating at 24 GHz, and devoted primarily to the retrieval of rain-rate structure by using the stereo-radar analysis, were presented in a previous study. This constitutes the starting point of the present paper, which analyzes the feasibility and scientific interest of adding a Doppler capability to the instrument. The scientific interest for Doppler data from space is investigated. Two components of the air velocity can be determined from the dual-beam spaceborne Doppler radar: the along-track component of the horizontal air velocity and a component directed between 0° and 20° off the vertical. Both components could be estimated with an accuracy of approximately 1.2 m s-1 within each resolution cell in standard conditions. Two ways to exploit these data are proposed: monitoring the mesoscale wind field within stratiform precipitation areas, or estimating the horizontal transport of vertical momentum associated with deep convection at the climatological scale. -from Authors