TITLE: GPS Integrated Precipitable Water (30-min) Data [CNRS]
DATA SET DOCUMENTATION (i.e. "Readme" file)
TITLE: French GPS-Met Data
AUTHOR(S): Observations: Joel Van Baelen
CNRS - CNRM/GAME
42 avenue G. Coriolis
31057 Toulouse, France
Tel: +33 - (0)5 - 61 07 96 07
Fax: +33 - (0)5 - 61 07 96 27
E-mail: joel.van-baelen@meteo.fr
FSL Data Processing: Seth I. Gutman
Chief, GPS-Met Observing Systems Branch
NOAA Forecast Systems Laboratory Demonstration Division
325 Broadway R/FS3
Boulder, CO 80305-3328
Phone: 303.497.7031
FAX: 303.497.6014
Email: Seth.I.Gutman@noaa.gov
Web: http://gpsmet.noaa.gov
1.0 DATA SET OVERVIEW:
See www.joss.ucar.edu/ihop/dm/archive/
2.0 INSTRUMENT DESCRIPTION:
See www.joss.ucar.edu/ihop/dm/archive/
3.0 DATA COLLECTION AND PROCESSING:
Data processed using GAMIT v 10.07 and SOPAC final orbits described in
sopac.ucsd.edu/processing/orbits.html
Derived parameters:
Zenith neutral (tropospheric) signal delay (ztd) and formal ztd error (FERR).
Zenith hydrostatic delay estimated from surface pressure adjusted to the height using the
Saastamoinen equation
Description of quality control procedures:
IPW flagged as questionable if ztd ferr > 12 mm.
Sfc. Met data flagged as suspect if they fail physical and temporal consistency checks.
Data intercomparisons, if applicable:
Nearest neighbor checks with other IHOP GPS-Met stations.
4.0 DATA FORMAT:
dimensions:
recNum = UNLIMITED ; // (7 currently)
staNamLen = 5 ;
staLongLen = 80 ;
variables:
char staNam(recNum, staNamLen) ;
staNam:long_name = "Alphanumeric station name" ;
char staLongNam(recNum, staLongLen) ;
staLongNam:long_name = "Station Location" ;
float staLat(recNum) ;
staLat:long_name = "Station Latitude" ;
staLat:units = "degrees north" ;
staLat:valid_range = -90., 90. ;
staLat:_FillValue = -99.9f ;
float staLon(recNum) ;
staLon:long_name = "Station Longitude" ;
staLon:units = " degrees east" ;
staLon:valid_range = -180., 180. ;
staLon:_FillValue = -999.9f ;
float staElev(recNum) ;
staElev:long_name = "Station Elevation (above MSL)" ;
staElev:units = "meters" ;
staElev:valid_range = 0., 8000. ;
staElev:_FillValue = -99.9f ;
double timeObs(recNum) ;
timeObs:string = "Mon May 13 00:15:00 " ;
timeObs:long_name = "Time of observation" ;
timeObs:units = "seconds since January 1 1970 00:00:00" ;
timeObs:_FillValue = -9999.9 ;
float waterVapor(recNum) ;
waterVapor:long_name = "Water Vapor" ;
waterVapor:units = "centimeters" ;
waterVapor:_FillValue = -9.9f ;
float pressure(recNum) ;
pressure:long_name = "Station pressure" ;
pressure:units = "millibars" ;
pressure:_FillValue = -999.f ;
char sfcMesType(recNum) ;
sfcMesType:long_name = "Type of surface measurements" ;
sfcMesType:units = "o = observed e = estimated" ;
sfcMesType:_FillValue = "*" ;
float temperature(recNum) ;
temperature:long_name = "Temperature used for calculation" ;
temperature:units = "Celsius" ;
temperature:_FillValue = -999.f ;
float relativeHumidity(recNum) ;
relativeHumidity:long_name = "Relative HumidityPercentTotal " ;
relativeHumidity:units = "Percent" ;
relativeHumidity:_FillValue = -99.f ;
float totalDelay(recNum) ;
totalDelay:long_name = "Total GPS signal delay" ;
totalDelay:units = "meters" ;
totalDelay:_FillValue = -99.f ;
float dryDelay(recNum) ;
dryDelay:long_name = "Dry component GPS signal delay" ;
dryDelay:units = "meters" ;
dryDelay:_FillValue = -99.f ;
float wetDelay(recNum) ;
wetDelay:long_name = "Wet component GPS signal delay" ;
wetDelay:units = "meters" ;
wetDelay:_FillValue = -99.f ;
float formalError(recNum) ;
formalError:long_name = "Formal Error" ;
formalError:units = "centimeters" ;
formalError:_FillValue = -0.8f ;
data:
staNam =
"BLAC",
"BREC",
"BURB",
"GUTH",
"MEDF",
"OILT",
"REDR" ;
staLongNam =
"Blackwell (MeteoFrance), OK",
"Breckenridge (MeteoFrance), OK",
"Burbank (MeteoFrance), OK",
"Guthrie (MeteoFrance), OK",
"Medford (MeteoFrance), OK",
"Oilton (MeteoFrance), OK",
"Red Rock (MeteoFrance), OK" ;
staLat = 36.75441, 36.41198, 36.63456, 35.84888, 36.79238, 36.03123,
36.35587 ;
staLon = -97.25451, -97.69392, -96.81043, -97.47977, -97.74593,
-96.49747,
-97.15304 ;
staElev = 304.1015, 352.4429, 301.6905, 300.5885, 331.355, 256.104,
294.3022 ;
timeObs = 1021248900, 1021248900, 1021248900, 1021248900, 1021248900,
1021248900, 1021248900 ;
waterVapor = 2.47, 1.81, -35.02, 2.33, 1.93, 3.31, 2.56 ;
pressure = 983.8, 983.8, 982.75, 980.5, 981.6, 987.4, 984.4 ;
sfcMesType = "ooooooo" ;
temperature = 11.8, 11.8, 12.15, 11.7, 11.45, 13.45, 12 ;
relativeHumidity = 94, 94, 94.5, 91, 91.5, 95.5, 95 ;
totalDelay = 2.3992, 2.3572, 0, 2.383, 2.3594, 2.4599, 2.4057 ;
dryDelay = 2.2418, 2.2419, 2.2257, 2.2344, 2.2368, 2.2501, 2.2432 ;
wetDelay = 0.1574, 0.1154, -2.2257, 0.1485, 0.1226, 0.2098, 0.1625 ;
formalError = 0.9, 0.9, -0.9, 1.5, 0.9, 0.9, 0.9 ;
5.0 DATA REMARKS:
Retrieved IPW is consistent with the FSL estimatess at nearby sites.
OILT: jump (~2- cm in north and ~2+ cmd in up in the beginning few days (up to
JD137).
BREC: a small N-S trend.
GUTH: large (+/- 10mm) E-W scatter
6.0 REFERENCES:
Saastamoinen, J., 1972 Introduction to Practical Computation of Astronomical
Refraction, Bull. Geod., 106, 383-397.
Bevis M., S. Businger, T.A. Herring, C. Rocken, R.A. Anthes and R.H. Ware, 1992. GPS
Meteorology: Remote Sensing of Atmospheric Water Vapor using the Global
Positioning System, J. Geophys. Res., 97, 15787-15801.