Potential of X-band spaceborne synthetic aperture radar for precipitation retrieval over land

Numerous space-borne X-band Synthetic Aperture Radars (X-SAR) systems will be launched by European agencies in the coming decade commencing this year. Those X-SARs can measure precipitation over land, thereby significantly augmenting the sensors that comprise the Global Precipitation Mission (GPM). This will incur relatively little incremental cost because they have already been funded. X-SAR measurements are especially beneficial over land where rainfall is difficult to measure by means of microwave radiometers that depend on scattering by frozen hydrometeors associated with that rain. The improved horizontal resolution of the retrievals will match the higher spatial resolution of mesoscale and general circulation models that will become available in the coming decade.