EOS Validation Program

Institution: NOAA/NESDIS Office of Research and Applications
                    NOAA Science Center
                    Suite 810, E/RA1
                    Camp Springs, MD 20746-4304
Phone: (301) 763-8136 x130
FAX: (301) 763-8136 x130
E-mail: James.G.Yoe@noaa.gov

Seth I. Gutman, NOAA/OAR Forecast Systems Laboratory

February 2003

Vertical column-integrated water vapor is among the Level 2 geophysical data products to be derived from AIRS observations. This project will help validate the AIRS integrated water vapor products by comparing to them nearly coincident observations made using surface-based Global Positioning System (GPS) receivers. A network of more than 90 of these GPS receivers is distributed over the continental United States and operated by the NOAA Forecast Systems Laboratory (FSL) for the purpose of monitoring total water vapor. The GPS total water vapor observations are accurate to within a few percent, are produced under all weather conditions, and are available for each site as 30-minute averages in near real time. The temporal resolution of the GPS total water vapor measurements and the spatial resolution of the AIRS observations will be sufficient to enable the collection of a large data set of collocated pairs of measurements. Statistical comparisons of AIRS and GPS data set will be made to validate the AIRS data and retrieval process. In addition, GPS water vapor products will be used to complement other AIRS water vapor validation studies, including those based on match-ups to radiosonde, water vapor radiometer, and lidar data.