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Evaluation of Refractivity Profiles from CHAMP and SAC-C GPS Radio OccultationThe CHAMP and SAC-C missions are the first missions to carry a second-generation 'Blackjack' GPS receiver. One of the new features of this receiver is its ability to sense the lower troposphere closer to the surface than the proof-of-concept GPS/MET 1995 experiment. Since their launch, CHAMP and SAC-C have collected thousands of GPS radio occultations, representing a wealth of measurements available for data assimilation in Numerical Weather Prediction (NWP) models. In order to evaluate the refractivity data derived by JPL from raw radio occultation measurements, we use Data Assimilation Office (DAO) 6-hour forecasts as an independent state of the atmosphere. We compare CHAMP and SAC-C refractivity (processed by JPL) with refractivity calculated from the DAO global fields of temperature, water vapor content and humidity. We will show statistics of the differences as well as Probability Density Functions (PDFs) of the differences. Depending upon availability of AIRS data, we plan to show individual profile comparisons between GPS radio occultation and AIRS retrievals.
Document ID
20020081277
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Poli, Paul
(NASA Goddard Space Flight Center Greenbelt, MD United States)
Joiner, Joanna
(NASA Goddard Space Flight Center Greenbelt, MD United States)
delaTorreJuarez, Manuel
(Jet Propulsion Lab., California Inst. of Tech. Pasadena, CA United States)
Hoff, Raymond M.
(Joint Center for Earth Systems Technology Baltimore, MD United States)
Atlas, Robert
Date Acquired
August 20, 2013
Publication Date
January 1, 2002
Subject Category
Geophysics
Meeting Information
Meeting: 1st International Workshop on Occultations for Probing Atmosphere and Climate
Location: Graz
Country: Austria
Start Date: September 16, 2002
End Date: September 20, 2002
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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