Re: Radar data in NetCDF

Hi Ag,

> Here at the British Atmospheric Data Centre (BADC) we are involved in the
> archival of numerous data products including radar data. We are encouraging
> the scientists that submit data to use the NetCDF format and comply with the
> Climate and Forecasts (CF) Metadata Conventions.
> 
> Radar data brings up some novel issues including a new set of potential
> standard names such as radial velocity and the use of decibels (non-UDunit!)
> as a unit. The reason I am writing to you is that I found your names in a
> discussion of the NetCDF Users' Group in 1995 where radar data was
> discussed. I am interested to know if you have pursued these issues further
> and whether there are any recent developments.
> 
> I look forward to hearing from you.

The local NetCDF User's Working Group stopped meeting and developing
conventions at that point, so no further NUWG conventions for radar
data were developed.

Don Murray pointed me to some information about existing netCDF
conventions for radar files that have been developed for data access
a few other institutions:

  http://www.met.rdg.ac.uk/radar/software/chil-doc-1.0/chil2nc.html
  http://www.atmos.washington.edu/~courtney/kwaj/UWproductsOnDAAC.html

and he said others could be found by Googling for "netcdf sweep file
format".

I've appended the CDL for a sample netCDF radar reflectivity dataset
from NSSL, if you're interested in what they developed.  It doesn't
follow CF conventions at all, but maybe some of the names might be of
use.

--Russ


netcdf Reflectivity_000.47_19950507-194552 {
dimensions:
        Azimuth = 367 ;
        Gate = 460 ;
variables:
        float Azimuth(Azimuth) ;
                Azimuth:Units = "Degrees" ;
        float BeamWidth(Azimuth) ;
                BeamWidth:Units = "Degrees" ;
        float GateWidth(Azimuth) ;
                GateWidth:Units = "Meters" ;
        float Reflectivity(Azimuth, Gate) ;
                Reflectivity:Units = "dBZ" ;

// global attributes:
                :TypeName = "Reflectivity" ;
                :DataType = "RadialSet" ;
                :Latitude = 32.573055267334 ;
                :Longitude = -97.3030548095703 ;
                :Height = 227.999999999916 ;
                :Time = 799875952 ;
                :FractionalTime = 0. ;
                :attributes = " ExpiryInterval Nyquist_Vel vcp" ;
                :ExpiryInterval-unit = "Minutes" ;
                :ExpiryInterval-value = "15" ;
                :Nyquist_Vel-unit = "Knots" ;
                :Nyquist_Vel-value = "53" ;
                :vcp-unit = "dimensionless" ;
                :vcp-value = "21" ;
                :Elevation = 0.46875 ;
                :ElevationUnits = "Degrees" ;
                :MissingData = -99900. ;
                :RangeFolded = -99901. ;
data:

 Azimuth = 77.61, 78.57, 79.63, 80.55, 81.56, 82.57, 83.54, 84.55, 85.52, 
    86.48, 87.5, 88.51, 89.52, 90.48, 91.45, 92.46, 93.38, 94.44, 95.45, 
    96.42, 97.38, 98.39, 99.32, 100.33, 101.29, 102.3, 103.32, 104.28, 
    105.29, 106.3, 107.31, 108.24, 109.25, 110.26, 111.23, 112.24, 113.2, 
    114.17, 115.18, 116.15, 117.11, 118.13, 119.09, 120.15, 121.11, 122.04, 
    123.09, 124.06, 125.02, 126.04, 127, 128.01, 128.98, 129.95, 130.91, 
    131.92, 132.93, 133.95, 134.91, 135.92, 136.93, 137.9, 138.87, 139.79, 
    140.8, 141.81, 142.82, 143.79, 144.76, 145.72, 146.65, 147.61, 148.67, 
    149.63, 150.64, 151.66, 152.62, 153.63, 154.64, 155.61, 156.62, 157.59, 
    158.6, 159.61, 160.58, 161.59, 162.55, 163.52, 164.53, 165.45, 166.46, 
    167.48, 168.44, 169.45, 170.38, 171.39, 172.35, 173.32, 174.33, 175.34, 
    176.35, 177.36, 178.37, 179.38, 180.35, 181.27, 182.33, 183.3, 184.26, 
    185.23, 186.2, 187.21, 188.17, 189.14, 190.2, 191.16, 192.17, 193.18, 
    194.15, 195.16, 196.13, 197.14, 198.11, 199.07, 200.08, 201.05, 202.02, 
    202.98, 203.95, 204.96, 205.97, 206.98, 207.99, 208.96, 209.93, 210.94, 
    211.86, 212.87, 213.88, 214.85, 215.86, 216.78, 217.79, 218.72, 219.64, 
    220.69, 221.7, 222.71, 223.68, 224.69, 225.7, 226.67, 227.64, 228.69, 
    229.61, 230.63, 231.64, 232.6, 233.66, 234.58, 235.59, 236.56, 237.48, 
    238.54, 239.55, 240.51, 241.52, 242.45, 243.41, 244.42, 245.39, 246.4, 
    247.41, 248.38, 249.43, 250.4, 251.41, 252.38, 253.34, 254.4, 255.32, 
    256.33, 257.3, 258.22, 259.23, 260.24, 261.17, 262.22, 263.19, 264.2, 
    265.21, 266.18, 267.19, 268.15, 269.17, 270.18, 271.14, 272.15, 273.08, 
    274.04, 275.05, 276.02, 277.03, 278.04, 279.01, 280.02, 280.99, 282, 
    282.96, 283.89, 284.94, 285.95, 286.92, 287.93, 288.85, 289.82, 290.79, 
    291.75, 292.76, 293.77, 294.79, 295.8, 296.76, 297.77, 298.74, 299.75, 
    300.76, 301.73, 302.7, 303.71, 304.67, 305.68, 306.65, 307.66, 308.58, 
    309.59, 310.61, 311.62, 312.58, 313.59, 314.52, 315.53, 316.54, 317.5, 
    318.52, 319.53, 320.49, 321.5, 322.47, 323.48, 324.45, 325.42, 326.43, 
    327.39, 328.36, 329.37, 330.34, 331.35, 332.27, 333.28, 334.34, 335.3, 
    336.31, 337.32, 338.25, 339.3, 340.22, 341.24, 342.25, 343.17, 344.22, 
    345.15, 346.11, 347.12, 348.09, 349.1, 350.11, 351.08, 352.13, 353.1, 
    354.07, 355.03, 355.96, 357.01, 358.02, 358.99, 0, 0.92, 1.89, 2.86, 
    3.78, 4.83, 5.8, 6.86, 7.82, 8.79, 9.8, 10.81, 11.78, 12.79, 13.75, 
    14.77, 15.78, 16.74, 17.75, 18.76, 19.73, 20.7, 21.62, 22.63, 23.64, 
    24.65, 25.62, 26.59, 27.55, 28.56, 29.53, 30.59, 31.55, 32.52, 33.57, 
    34.54, 35.55, 36.52, 37.49, 38.5, 39.46, 40.47, 41.44, 42.36, 43.37, 
    44.38, 45.35, 46.36, 47.33, 48.38, 49.35, 50.32, 51.33, 52.29, 53.31, 
    54.32, 55.24, 56.29, 57.22, 58.18, 59.19, 60.16, 61.17, 62.18, 63.15, 
    64.16, 65.13, 66.14, 67.06, 68.03, 69.04, 70.05, 71.06, 72.07, 72.99, 
    73.96, 74.88, 75.89, 76.9, 77.87, 78.88 ;
}