GPS Instrumentation Specification and Performance John J. Braun COSMIC Program University Corporation for Atmospheric Research Boulder, Colorado

Outline GPS Stations Operating for IHOP Network Operation and Data Collection Percentage Homestead Site General Network Statistics Data Products Precipitable Water Vapor Slant Water Vapor Tomography Solutions

GPS Stations In IHOP Region NOAA/FSL and DOT Stations OU/ARM/SuomiNet Stations Special Stations for IHOP 41 Stations Total Map of Central United States. GPS stations used in IHOP are shown.

Acknowledgements CNRS - CNRM/GAME - France (contact: Joel Van Baelen) NOAA Forecast Systems Laboratory (contact: Seth Gutman) University of Oklahoma (contact: Randy Peppler) ARM Program (contact: James Liljegren) NASA/GSFC (contact: Dave Whiteman)

Homestead (SA14) Data Collection Homestead GPS station data collection percentage. Generally, worked well - days133, 167, 173 are all short in time.

ARM CF (SG01) Data Collection ARM CF SuomiNet station data collection percentage. First week or so, data not available, but after day 150 things worked ok.

French Station (BLAC) Data Collection

GPS Data Products Data Product Time Resolution Accuracy Location PW 30 Min 1.5 mm Station Specific SW 2 Min ~1.5 mm Tomography 15 Min ??? (g/m3) ARM CF Region Vital Specifications of PW Data

GPS PW and SW and Descriptions PWV SW SW is the integrated water vapor along single GPS ray paths PWV is the average (estimate) of all SW observations in a cone scaled to zenith Simultaneous observations along 8-12 GPS ray paths GPS and WVR sensed SW and PWV agree to ~1.5 mm rms

Precipitable Water Vapor Animated PW map of IHOP region

Slant Water Vapor Homestead Slant Wate Vapor (right) on day when dryline formed and oscillated over Homestead site. Refractivity measurements from SPOL radar are shown on the left.

Example of SW During Storm Example of polar sky plots of SW. Note the difference in azimuthal variability between the station in the clear air region and the station under the convective cell. Fifteen minutes of observations are plotted here.

International H20 Project Tomography Solution Example skyplots of SWV during IHOP. The station under the clear sky has less azimuthal variability than the station under the convective cell.

Conclusions 41 GPS Stations in IHOP_2002 Region Homestead station had high percentage of data availability PW (30 min), SW (2 min), and Tomography Solutions Available All GPS data are processed. PW data are available at JOSS web site. If someone is interested in SW and/or tomography data, they should contact me directly (braunj@ucar.edu).