Title: GeoSTAR final results
Presenting Author: Bjorn Lambrigtsen
Organization: Jet Propulsion Laboratory

Abstract:
The Geostationary Synthetic Thinned Aperture Radiometer (GeoSTAR) is a microwave sounder intended for the Precipitation and All-weather Temperature and Humidity (PATH) mission, one of 15 missions that the National Research Council (NRC) recommended in 2007 that NASA undertake and consists of placing a microwave sounder on a geostationary satellite to observe rapidly evolving atmospheric processes such as hurricanes and other severe weather. The NRC recommended that PATH be implemented with a microwave array spectrometer. The GeoSTAR design was and still is the only array spectrometer solution, and NASA has therefore continued to fund advancement of the technology required to implement GeoSTAR for PATH, in IIP-07 and now in IIP-10, which was completed May 31, 2015. The maturity of all key technologies is now sufficient that the development of the PATH mission can commence. The toughest challenge was to develop a correlator ASIC that can meet the PATH requirements for speed and power consumption. Such a chip has now been developed with the help of our colleagues at the University of Michigan. Secondary goals have been to build a complete fully functional 183-GHz array of miniature high performance receivers, which are assembled by NexGen through an SBIR contract, using LNAs developed in collaboration with NGC and fabricated by them. A small demonstration mission could be funded through the Venture program in the near future. The full PATH mission is currently classified as a tier-3 mission, but with the rapid progress in the technology development, it is now feasible to advance PATH to the pre-formulation phase. We will discuss the specific advances in the technology achieved and present test results for the new correlator ASIC as well as tests with a full system, including imaging at 183 GHz. Copyright 2015 California Institute of Technology. Government sponsorship acknowledged.