Processing GPS Occultation Data To Characterize Atmosphere

NASA Tech Briefs, Mar 2005 by Hajj, George, Kursinski, Emil, Leroy, Stephen, Iijima, Byron, Et al

NASA's Jet Propulsion Laboratory, Pasadena, California

GOAS [Global Positioning System (GPS) Occultation. Analysis System] is a computer program that accepts signal-occultation data from GPS receivers aboard low-Earth-orbiting satellites and processes the data to characterize the terrestrial atmosphere and, in somewhat less comprehensive fashion, the ionosphere. GOAS is very robust and can be run in an unattended semi-operational processing mode. It features sophisticated retrieval algorithms that utilize the amplitudes and phases of the GPS signals. It incorporates a module that, using an assumed atmospheric refractivity profile, simulates the effects of the retrieval processing system, including the GPS receiver. GOAS utilizes the GIPSY software for precise determination of orbits as needed for calibration. The GOAS output for the Earth's troposphere and mid-to-lower stratosphere consists of high-resolution (

This program was written by George Hajj, Emil Kursinski, Stephen Leroy, Byron Iijima, Manuel de la Torre Juarez, Larry Romans, and Chi Ao of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Software category.

This software is available for commercial licensing. Please contact Don Hart of the California Institute of Technology at (818) 393-3425. Refer to NPO-30596.