GeoSTAR – a new hurricane observatory

The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a microwave sounder under development at NASA's Jet Propulsion Laboratory (JPL) that has capabilities similar to the Advanced Microwave Sounding Unit (AMSU) sounders currently operating on NASA and NOAA low-earth-orbiting satellites. GeoSTAR will provide similar capabilities from geostationary orbit, which enables continuous monitoring of the visible hemisphere. Microwave sounders, such as AMSU and GeoSTAR, measure the 3-dimensional structure of temperature, water vapor, cloud liquid water, precipitation and other derived parameters under a wide range of weather conditions, including full cloud cover. With a recently developed method, described in a separate paper, it will even be possible to measure the convective structure and precipitation in three dimensions. These capabilities make a geostationary sounder especially valuable as a hurricane observatory. This was recognized by the National Research Council, which recommended that a GeoSTAR-like sensor be developed for a “Precipitation and All-weather Temperature and Humidity” (PATH) mission. With GeoSTAR, whether through the PATH mission or as part of an operational mission such as NOAA's new series of geostationary satellites, the GOES-R series, it will be possible to measure these parameters every 15-20 minutes for most of the hemisphere. This will make GeoSTAR a key hurricane and severe-storm observatory. The enabling aperture synthesis concept that GeoSTAR is based on has been developed and demonstrated at JPL, and all required technology elements will be in place in less than 2 years, and GeoSTAR can soon be deployed in space. We discuss the status of the GeoSTAR development, possible mission scenarios and some of the science applications.

Copyright 2009 California Institute of Technology. Government sponsorship acknowledged.