File Descriptions of UW GV Products on DAAC

1C51UW

• Format: Universal Format (UF); described in BAMS, Vol 61, No 11, November 1980, pp. 1401-1404

• Filenaming Convention: 1C51UW.kwaj.YYYYMMMDD.HHMM.uf

• Description:

  Raw sigmet files are converted to UF format via the RSL (qlook).

  All fields in the UF files that contain reflectivity values are calibrated by addition of a constant. The calibration constant is scaled by 100 and stored in the UF files in all the applicable field headers, word 17 (referred to in documentation as "edit code"). The actual calibration constant is the value in the UF header divided by 100. cal_const has been added to the ray header in the RSL so that anyone using the RSL to work with the 1C51UW data can easily extract the calibration constant.

  After calibration, the reflectivity values in the UF files are quality controlled. Since ZT contains the most raw form of the reflectivity measurements, the QC is applied to ZT, if available. Otherwise, the QC is applied to the DZ field. The 1C51UW UF files contain 3 fields:

  • 1. DZ -- reflectivity field on which QC operates; if QC operates on ZT, then ZT is relabelled DZ and stored in 1C51UW product; if QC operates on DZ, then DZ is stored in 1C51UW product
  • 2. CZ -- corrected (QC'd) reflectivity
  • 3. VR -- radial velocity

baseUW

• Format: netCDF

• Filenaming Convention: baseUW.kwaj.YYYYMMDD.HHMMSS.cdf

• Description:

  Single level, cartesian grids containing output of NCAR SPRINT interpolation of lowest sweep of 1C51UW. Horizontal extent is 150x150km and horizontal resolution is 2km. Note that in the netCDF files, "alt" (altitude) is assigned the elevation angle of the lowest sweep (which is used to create this product) and "z_spacing" has no meaning.

• Sample CDL:

  netcdf baseUW.kwaj.19990701.000232 {
  dimensions:
          time = UNLIMITED ; // (1 currently)
          x = 151 ;
          y = 151 ;
          z = 1 ;
  variables:
          float maxdz(time, z, y, x) ;
                  maxdz:missing_value = -32768.f ;
          int base_time ;
          float time_offset(time) ;
          float lat ;
          float lon ;
          float alt ;
          float x_spacing ;
          float y_spacing ;
          float z_spacing ;
  }
  

2A53UW

• Format: netCDF

• Filenaming Convention: 2A53UW.kwaj.YYYYMMDD.HHMMSS.cdf

• Description:

  Instantaneous rain rate cartesian grid based on baseUW and 2A54UW. Units are mm/hr. Min range is 17 km, max range is 150 km. Note that in the netCDF files, "alt" (altitude) is assigned the elevation angle of the lowest sweep (which is used to create baseUW) and "z_spacing" has no meaning.

• Sample CDL:

  netcdf 2A53UW.kwaj.19990701.000232 {
  dimensions:
          time = UNLIMITED ; // (1 currently)
          x = 151 ;
          y = 151 ;
          z = 1 ;
  variables:
          int base_time ;
          int time_offset(time) ;
          float lat ;
          float lon ;
          float alt ;
          float x_spacing ;
          float y_spacing ;
          float z_spacing ;
          float rainr(time, z, y, x) ;
                  rainr:missing_value = -32768.f ;
  }
  

2A54UW

• Format: netCDF

• Filenaming Convention: 2A54UW.kwaj.YYYYMMDD.HHMMSS.cdf

• Description:

  Instantaneous convective-stratiform cartesian grid based on baseUW. Values are 0 (no echo), 1 (stratiform), and 2 (convective). Min range is 17 km, max range is 150 km. Note that in the netCDF files, "alt" (altitude) is assigned the elevation angle of the lowest sweep (which is used to create baseUW) and "z_spacing" has no meaning.

• Sample CDL:

  netcdf 2A54UW.kwaj.19990701.000232 {
  dimensions:
          time = UNLIMITED ; // (1 currently)
          x = 151 ;
          y = 151 ;
          z = 1 ;
  variables:
          int base_time ;
          int time_offset(time) ;
          float lat ;
          float lon ;
          float alt ;
          float x_spacing ;
          float y_spacing ;
          float z_spacing ;
          float convsf(time, z, y, x) ;
                  convsf:missing_value = -32768.f ;
  }
  

2A55UW

• Format: netCDF

• Filenaming Convention: 2A55UW.kwaj.YYYYMMDD.HHMMSS.cdf

• Description:

  Multiple-level cartesian grid containing output of NCAR SPRINT interpolation of CZ and VR fields of 1C51UW. Horizontal extent is 150x150km and resolution is 2km. Vertical range is 2-15km and resolution is 1km. Unlike other products, 2A55UW is not created for every volume but only for volumes of interest. These are defined as volumes within +/-15 minutes of overpass times and volumes with significant rainfall (areal rainfall rate >= 0.15mm/hr).

• Sample CDL:

  netcdf 2A55UW.kwaj.19990701.092242 {
  dimensions:
          time = UNLIMITED ; // (1 currently)
          x = 151 ;
          y = 151 ;
          z = 14 ;
  variables:
          float maxdz(time, z, y, x) ;
                  maxdz:missing_value = -32768.f ;
          float radialvelocity(time, z, y, x) ;
                  radialvelocity:missing_value = -32768.f ;
          int base_time ;
          float time_offset(time) ;
          float lat ;
          float lon ;
          float alt ;
          float x_spacing ;
          float y_spacing ;
          float z_spacing ;
  }
  

3A54UW

• Format: netCDF

• Filenaming Convention: 3A54UW.kwaj.YYYYMM.cdf

• Description:

  Monthly rain accumulation cartesian grid based on 2A53UW. Units are mm. Min range is 17 km, max range is 150 km. Horizontal extent is 150x150km and resolution is 2km. Note that in the netCDF files, "alt" (altitude) is assigned the elevation angle of the lowest sweep (which is used to create baseUW) and "z_spacing" has no meaning.

  Nine fields are present. "raccumbest" is the best overall estimate and the other eight fields are indicators of uncertainty. The names of those variables are self-explanatory.

• Sample CDL:

  netcdf 3A54UW.kwaj.199912 {
  dimensions:
  	time = UNLIMITED ; // (1 currently)
  	x = 151 ;
  	y = 151 ;
  	z = 1 ;
  variables:
  	int base_time ;
  	int time_offset(time) ;
  	float lat ;
  	float lon ;
  	float alt ;
  	float x_spacing ;
  	float y_spacing ;
  	float z_spacing ;
  	float raccumbest(time, z, y, x) ;
  		raccumbest:missing_value = -32768.f ;
  	float raccumgaplo(time, z, y, x) ;
  		raccumgaplo:missing_value = -32768.f ;
  	float raccumgaphi(time, z, y, x) ;
  		raccumgaphi:missing_value = -32768.f ;
  	float raccumzrlo(time, z, y, x) ;
  		raccumzrlo:missing_value = -32768.f ;
  	float raccumzrhi(time, z, y, x) ;
  		raccumzrhi:missing_value = -32768.f ;
  	float raccumcallo(time, z, y, x) ;
  		raccumcallo:missing_value = -32768.f ;
  	float raccumcalhi(time, z, y, x) ;
  		raccumcalhi:missing_value = -32768.f ;
  	float raccumvplo(time, z, y, x) ;
  		raccumvplo:missing_value = -32768.f ;
  	float raccumvphi(time, z, y, x) ;
  		raccumvphi:missing_value = -32768.f ;
  }