Stepped-Frequency Microwave Radiometer
Versions 1 and 2 are g-zipped ASCII files, Version 3 is in NetCDF format.
|
Date | is YYYYMMDD (like the file name) |
Time | is HHMMSS (hour,minute,second) UTC |
Lon | is decimal longitude (negative west) |
Lat | is decimal latitude |
Alt | is radar altitude (meters) of aircraft |
Pres | is flight-level pressure (milibars) |
Rad | is radial distance to storm center (kilometers) |
Az | is clockwise azimuth angle (degrees) of measurement relative to storm motion direction (e.g. 45 deg. is in the right-front quadrant of the storm). |
Sfc WS | is the surface windspeed measurement from the SFMR (meters/second) |
Fltlvl WS | is the windspeed at flight-level (meters/second) |
Fltlvl WDIR | is the wind direction at flight level (degrees) |
Version 2 (ASCII)
The data files containing surface windspeeds measured by the SFMR are ascii columnar time series of data, recorded at a nominal rate of 1 Hz. The 12 columns contain the following data:
Date | is YYYYMMDD (like the file name) |
Time | is HHMMSS (hour,minute,second) UTC |
Lon | is decimal longitude (negative west) |
Lat | is decimal latitude |
Alt | is radar altitude (meters) of aircraft |
Pres | is flight-level pressure (milibars) |
Rad | is radial distance to storm center (kilometers) |
Az | is clockwise azimuth angle (degrees) of measurement relative to storm motion direction (e.g. 45 deg. is in the right-front quadrant of the storm). |
Sfc WS | is the surface windspeed measurement from the SFMR (meters/second) |
RR | is the path-mean rain rate (mm/hr) |
Fltlvl WS | is the windspeed at flight-level (meters/second) |
Fltlvl WDIR | is the wind direction at flight level (degrees) |
Wind data (both surface and flight-level) are filtered to 10-second averages along the flight track. Processing details, as well as correction factors applied to the measurements can be found in:
Version 3 (NetCDF)
These data files are now encoded in NCAR's NetCDF format. Each file contains data from one flight. The files are named according to the convention:AAAA_SFMRYYYYMMDD[AC].nc
AAAA is the aircraft agency NOAA for AOC aircraft or AFRC for Air Force.
"_SFMR" denotes a Stepped Frequncy Microwave Radiometer file.
YYYYMMDD is the starting year, month, and day of the mission
[AC] is the aircraft ID (H=N42RF, I=N43RF,
U=Air Force)
followed by the sequential number of that flight for the day.
".nc" designates a NetCDF file
(examples: AFRC_SFMR20110823U1.nc NOAA_SFMR20140916H1.nc)
Here is a listing of the parameters as recorded in the SFMR files
netcdf NOAA_SFMR20050828I1 { dimensions: time = 34172 ; variables: int DATE(time) ; DATE:units = "YYYYMMDD" ; DATE:valid_range = 0, 100000000 ; DATE:C_format = "%.8d" ; DATE:long_name = "Date" ; int TIME(time) ; TIME:units = "HHMMSS UTC" ; TIME:valid_range = 0, 235959 ; TIME:C_format = "%.6d" ; TIME:long_name = "Time" ; float LON(time) ; LON:units = "deg. E." ; LON:valid_range = -180.f, 180.f ; LON:C_format = "%8.3f" ; LON:long_name = "Longitude" ; float LAT(time) ; LAT:units = "deg. N." ; LAT:valid_range = -90.f, 90.f ; LAT:C_format = "%8.3f" ; LAT:long_name = "Latitude" ; float RALT(time) ; RALT:units = "m" ; RALT:valid_range = 0.f, 9999.f ; RALT:C_format = "%9.1f" ; RALT:long_name = "Radar altitude" ; float RANG(time) ; RANG:units = "deg." ; RANG:valid_range = -30.f, 30.f ; RANG:C_format = "%8.2f" ; RANG:long_name = "Roll angle" ; float PANG(time) ; PANG:units = "deg." ; PANG:valid_range = -30.f, 30.f ; PANG:C_format = "%8.2f" ; PANG:long_name = "Pitch angle" ; float ATEMP(time) ; ATEMP:units = "deg. Celsius" ; ATEMP:valid_range = -60.f, 60.f ; ATEMP:C_format = "%7.1f" ; ATEMP:long_name = "Air temperature" ; float SST(time) ; SST:units = "deg. Celsius" ; SST:valid_range = 22.f, 36.f ; SST:C_format = "%7.2f" ; SST:long_name = "Sea-surface temperature" ; float SALN(time) ; SALN:units = "g/kg" ; SALN:valid_range = 35.f, 37.f ; SALN:C_format = "%7.1f" ; SALN:long_name = "Salinity" ; float SWS(time) ; SWS:units = "m/s" ; SWS:valid_range = 0.f, 999.f ; SWS:C_format = "%9.1f" ; SWS:missing_value = -999.9f ; SWS:long_name = "SFMR wind speed" ; float SRR(time) ; SRR:units = "mm/hr" ; SRR:valid_range = 0.f, 999.f ; SRR:C_format = "%9.1f" ; SRR:missing_value = -999.9f ; SRR:long_name = "SFMR rain rate" ; float FWS(time) ; FWS:units = "m/s" ; FWS:valid_range = 0.f, 999.f ; FWS:C_format = "%9.1f" ; FWS:long_name = "Flt. lvl. wind speed" ; float FDIR(time) ; FDIR:units = "deg. meteor." ; FDIR:valid_range = 0.f, 360.f ; FDIR:C_format = "%9.1f" ; FDIR:long_name = "Flt. lvl. wind direction" ; int FLAG(time) ; FLAG:units = "unitless" ; FLAG:valid_range = 0, 3 ; FLAG:C_format = "%.1d" ; FLAG:valid_data = 0 ; FLAG:questionable_data = 1 ; FLAG:invalid_data = 2 ; FLAG:no_solution = 3 ; FLAG:long_name = "Validity flag" ; int NGC(time) ; NGC:units = "channels" ; NGC:valid_range = 0, 6 ; NGC:C_format = "%.1d" ; NGC:long_name = "Number of channels" ; float TB1(time) ; TB1:units = "Kelvin" ; TB1:valid_range = 0.f, 325.f ; TB1:C_format = "%7.1f" ; TB1:missing_value = -999.9f ; TB1:long_name = "Bright. Temp. (4.74 GHz)" ; float TB2(time) ; TB2:units = "Kelvin" ; TB2:valid_range = 0.f, 325.f ; TB2:C_format = "%7.1f" ; TB2:missing_value = -999.9f ; TB2:long_name = "Bright. Temp. (5.31 GHz)" ; float TB3(time) ; TB3:units = "Kelvin" ; TB3:valid_range = 0.f, 325.f ; TB3:C_format = "%7.1f" ; TB3:missing_value = -999.9f ; TB3:long_name = "Bright. Temp. (5.57 GHz)" ; float TB4(time) ; TB4:units = "Kelvin" ; TB4:valid_range = 0.f, 325.f ; TB4:C_format = "%7.1f" ; TB4:missing_value = -999.9f ; TB4:long_name = "Bright. Temp. (6.02 GHz)" ; float TB5(time) ; TB5:units = "Kelvin" ; TB5:valid_range = 0.f, 325.f ; TB5:C_format = "%7.1f" ; TB5:missing_value = -999.9f ; TB5:long_name = "Bright. Temp. (6.69 GHz)" ; float TB6(time) ; TB6:units = "Kelvin" ; TB6:valid_range = 0.f, 325.f ; TB6:C_format = "%7.1f" ; TB6:missing_value = -999.9f ; TB6:long_name = "Bright. Temp. (7.09 GHz)" ; // global attributes: :Source = "NOAA/AOML/HRD/" ; :Project = "SFMR hurricane surface winds" ; :Update = "Reprocessed using 2015 operational algorithm" ; :FlightDate = "2005/08/28" ; :Aircraft = "NOAA43" ; :TimeInterval = "16:08:51-01:54:10" ; :StormName = "Katrina" ; |
Questions or comments, contact
Heather Holbach
Last update 2017/03/14