netcdf frf/oceanography/waves/waverider-26m/waverider-26m.ncml {
  dimensions:
    station_name_length = 31;
    waveFrequency = 62;
    waveDirectionBins = 72;
    time = 263919;
  variables:
    char station_name(station_name_length=31);
      :units = ;
      :long_name = "station name";
      :cf_role = "timeseries_id";
      :short_name = "station_name";
      :_ChunkSizes = 31U; // uint

    double latitude;
      :_FillValue = -999.0; // double
      :units = "degrees_north";
      :standard_name = "latitude";
      :long_name = "Latitude";
      :short_name = "lat";

    double longitude;
      :_FillValue = -999.0; // double
      :units = "degrees_east";
      :standard_name = "longitude";
      :long_name = "Longitude";
      :short_name = "lon";

    float nominalDepth;
      :_FillValue = -999.0f; // float
      :units = "m";
      :description = "Nominal bottom vertical location from NAVD88";
      :long_name = "Bottom Elevation (NAVD88)";
      :short_name = "Bottom Elevation";

    float waveFrequency(waveFrequency=62);
      :_FillValue = -999.0f; // float
      :units = "s-1";
      :standard_name = "wave_frequency";
      :long_name = "Spectral Band Center Frequency";
      :short_name = "Frequency";
      :_ChunkSizes = 62U; // uint

    float waveDirectionBins(waveDirectionBins=72);
      :_FillValue = -999.0f; // float
      :units = "degree";
      :long_name = "Band Center in Degrees";
      :short_name = "Direction";
      :_ChunkSizes = 72U; // uint

    double time(time=263919);
      :_FillValue = -999.0; // double
      :units = "seconds since 1970-01-01 00:00:00";
      :standard_name = "time";
      :long_name = "UTC Sample Time";
      :calendar = "gregorian";
      :short_name = "time";
      :_ChunkSizes = 1000U; // uint

    float gaugeDepth(time=263919);
      :_FillValue = -999.0f; // float
      :units = "m";
      :long_name = "Sensor Depth Using Pressure, relative to mean water level";
      :short_name = "Gauge Depth";
      :_ChunkSizes = 1488U; // uint

    float waveHs(time=263919);
      :_FillValue = -999.0f; // float
      :units = "m";
      :standard_name = "sea_surface_wave_significant_height";
      :long_name = "Significant Wave Height";
      :description = "Significant wave height computed for spectral frquencies between 0.04 and 0.5 Hz";
      :short_name = "Hs";
      :coordinates = "lat lon";
      :_ChunkSizes = 1488U; // uint

    float waveTp(time=263919);
      :_FillValue = -999.0f; // float
      :units = "s";
      :standard_name = "sea_surface_wave_period_at_variance_spectral_density_maximum";
      :description = "Period of a parobolic fit to the peak of the energy density spectrum using the peak and two surrounding points.  Computed for wave periods between 2 and 25 seconds";
      :long_name = "Peak Spectral Period Between 2 and 25 Seconds";
      :coordinates = "lat lon";
      :short_name = "Tp";
      :_ChunkSizes = 1488U; // uint

    float waveTpfb(time=263919);
      :_FillValue = -999.0f; // float
      :units = "s";
      :long_name = "Peak Wave Period Over Full Spectrum";
      :description = "Period of a parobolic fit to the peak of the energy density spectrum using the peak and two surrounding points. Computed over entire spectrum";
      :coordinates = "lat lon";
      :short_name = "Tp-FullBand";
      :_ChunkSizes = 1488U; // uint

    float waveTm(time=263919);
      :_FillValue = -999.99f; // float
      :units = "s";
      :standard_name = "sea_surface_wave_mean_period_from_variance_spectral_density_inverse_frequency_moment";
      :description = "Period for the mean of the energy density spectrum";
      :long_name = "Mean Spectral Period";
      :coordinates = "lat lon";
      :short_name = "Tm";
      :_ChunkSizes = 1488U; // uint

    float waveTm1(time=263919);
      :_FillValue = -999.99f; // float
      :units = "s";
      :standard_name = "sea_surface_wave_mean_period_from variance_spectral_density_first_frequency_moment";
      :description = "Period for the 1st moment mean of the energy density spectrum";
      :long_name = " 1st Moment Mean Spectral Period";
      :coordinates = "lat lon";
      :short_name = "Tm1";
      :_ChunkSizes = 1488U; // uint

    float waveTm2(time=263919);
      :_FillValue = -999.99f; // float
      :units = "s";
      :standard_name = "sea_surface_wave_mean_period_from variance_spectral_density_second_frequency_moment";
      :description = "Period for the 2nd moment mean of the energy density spectrum";
      :long_name = " 2nd Moment Mean Spectral Period";
      :coordinates = "lat lon";
      :short_name = "Tm2";
      :_ChunkSizes = 1488U; // uint

    float wavePeakDirectionPeakFrequency(time=263919);
      :_FillValue = -999.0f; // float
      :units = "degree";
      :standard_name = "sea_surface_wave_from_direction";
      :description = "Wave direction is from true north (MET convention)";
      :long_name = "Wave Direction at the Peak of the Frequency-Direction Spectrum";
      :coordinates = "lat lon";
      :short_name = "thetaP";
      :_ChunkSizes = 1488U; // uint

    float waveMeanDirection(time=263919);
      :_FillValue = -999.0f; // float
      :units = "degree";
      :description = "Wave direction is from true north (MET convention), energy weighted over and computed from a1 & b1";
      :long_name = "Mean Wave Direction of 2D Spectrum";
      :coordinates = "lat lon";
      :short_name = "thetaM";
      :_ChunkSizes = 1488U; // uint

    float waveMeanDirectionPeakFrequency(time=263919);
      :_FillValue = -999.0f; // float
      :units = "degree";
      :description = "Wave direction is from true north (MET convention), energy weighted at peak frequency";
      :long_name = "Wave Mean Direction at the Peak Frequency";
      :coordinates = "lat lon";
      :short_name = "thetaMp";
      :_ChunkSizes = 1488U; // uint

    float wavePrincipleDirection(time=263919);
      :_FillValue = -999.0f; // float
      :units = "degree";
      :description = "Wave direction is from true north (MET convention), energy weighted over and computed from a2 & b2";
      :long_name = "Wave Principle Direction of 2D Spectrum";
      :coordinates = "lat lon";
      :short_name = "thetaM2";
      :_ChunkSizes = 1488U; // uint

    float waveEnergyDensity(time=263919, waveFrequency=62);
      :_FillValue = -999.0f; // float
      :units = "m2 s";
      :standard_name = "sea_surface_wave_variance_spectral_density";
      :long_name = "Energy Density";
      :short_name = "1D Wave Energy";
      :_ChunkSizes = 1488U, 62U; // uint

    float directionalWaveEnergyDensity(time=263919, waveFrequency=62, waveDirectionBins=72);
      :_FillValue = NaNf; // float
      :units = "m2 s deg-1";
      :standard_name = "sea_surface_wave_directional_variance_spectral_density";
      :long_name = "2D Wave Energy Density Spectrum";
      :short_name = "Energy Density";
      :_ChunkSizes = 1U, 62U, 72U; // uint

    byte qcFlagE(time=263919);
      :_FillValue = -99B; // byte
      :units = ;
      :description = "Realtime QC flags for spectral estimates";
      :long_name = "Quality Control Flag Value for Energy Estimates";
      :flag_meanings = "1=passed, 2=not set, 3=questionable, 4=failed";
      :coordinates = "lat lon";
      :short_name = "QC_flag_E";
      :_ChunkSizes = 1488U; // uint

    byte qcFlagD(time=263919);
      :_FillValue = -99B; // byte
      :units = ;
      :description = "Realtime QC flags for spectral direction estimates";
      :long_name = "Quality Control Flag Value for Directional Spectra Estimates";
      :flag_meanings = "1=passed, 2=not set, 3=questionable, 4=failed";
      :coordinates = "lat lon";
      :short_name = "QC_flag_D";
      :_ChunkSizes = 1488U; // uint

    float directionalPeakSpread(time=263919);
      :_FillValue = -999.0f; // float
      :units = "deg";
      :description = "Directional spread at peak frequency with cos(2*theta) circular moments";
      :long_name = "Directional Spectra Spread at Peak Frequency";
      :coordinates = "lat lon";
      :short_name = "spreadP";
      :_ChunkSizes = 1488U; // uint

    float spectralWidthParameter(time=263919);
      :_FillValue = -999.0f; // float
      :units = ;
      :description = "Spectral width of 1D spectra, (m0*m4 - m2^2)/(m0*m4)  (Cartwright & Longuet-Higgins, 1956)";
      :long_name = "Spectral Width Parameter";
      :valid_min = "0";
      :valid_max = "1";
      :coordinates = "lat lon";
      :short_name = "spreadP";
      :_ChunkSizes = 1488U; // uint

    byte waveDirectionEstimator(time=263919);
      :_FillValue = 0B; // byte
      :units = ;
      :description = "Estimator for directional spectra - 1,4,6 = IMLE, 5,7=Longuet-Higgins cos(2*theta)";
      :long_name = "Directional Spectra Estimator";
      :coordinates = "lat lon";
      :short_name = "Wave Direction";
      :_ChunkSizes = 1488U; // uint

    float waveA1Value(time=263919, waveFrequency=62);
      :_FillValue = -999.0f; // float
      :units = ;
      :description = "a1 Fourier coefficient";
      :long_name = "a1 Directional Fourier Coefficient";
      :coordinates = "lat lon";
      :short_name = "a1";
      :_ChunkSizes = 1488U, 62U; // uint

    float waveB1Value(time=263919, waveFrequency=62);
      :_FillValue = -999.0f; // float
      :units = ;
      :description = "b1 Fourier coefficient";
      :long_name = "b1 Directional Fourier Coefficient";
      :coordinates = "lat lon";
      :short_name = "b1";
      :_ChunkSizes = 1488U, 62U; // uint

    float waveA2Value(time=263919, waveFrequency=62);
      :_FillValue = -999.0f; // float
      :units = ;
      :description = "a2 Fourier coefficient";
      :long_name = "a2 Directional Fourier Coefficient";
      :coordinates = "lat lon";
      :short_name = "a2";
      :_ChunkSizes = 1488U, 62U; // uint

    float waveB2Value(time=263919, waveFrequency=62);
      :_FillValue = -999.0f; // float
      :units = ;
      :description = "b2 Fourier coefficient";
      :long_name = "b2 Directional Fourier Coefficient";
      :coordinates = "lat lon";
      :short_name = "b2";
      :_ChunkSizes = 1488U, 62U; // uint

  // global attributes:
  :featureType = "timeSeries";
  :title = "FRF 26m Datawell Waverider Buoy";
  :summary = "USACE/COAB collected directional wave data with a Datawell Directional Waverider (Mk III) approximately \n 10 miles (16.1 km) offshore of Duck (FRF), NC. The nominal depth for each deployment was approximately \n 26m NAVD88. Directional spectra Fourier coefficients are computed onboard the buoy and transmitted via \n Iridium satellite link at half-hour intervals, raw data record lengths are 30 minutes. The USACE funds this\n data collection through the Coastal Data Information Program (CDIP), UCSD San Diego, CA.  The buoy computed \n Directional Fourier coefficients are provided but have been rotated from magnetic north to clockwise from \n true north.  Two dimensional (2D) frequency-direction spectra are computed using an Maximum Likelihood Estimator\n (MLE) method.  See - Oltman-Shay, J., Guza, R.T., 1984. A data-adaptive ocean wave directional-spectrum \n estimator for pitch and roll type measurements. Journal of Physical Oceanography 14, 1800–1810. \n This buoy has other identifiers; 44100 at the National Data Buoy Center (NDBC), 430 at CDIP and the FRF.\n";
  :history = "2008-05-22:dataset created";
  :source = "In situ observations from FRF-ocean_waves_waverider-26m_YYYYMM.mat";
  :sourceUrl = "(local files)";
  :standard_name_vocabulary = "CFv25";
  :Metadata_Conventions = "Unidata Dataset Discovery v1.0, CF-1.6";
  :metadata_link = "N/A";
  :Conventions = "CF-1.6";
  :creator_name = "USACE/CHL/COAB";
  :creator_url = "http://www.frf.usace.army.mil";
  :creator_email = "frfwebmaster@usace.army.mil";
  :license = "These data may be redistributed and used without restriction. Data are intended for scholarly use by the research community, with the express agreement that users will properly acknowledge the USACE Field Research Facility and the supporting investigator(s). Use or reproduction of these data for commercial purposes is prohibited without prior written permission.";
  :keywords_vocabulary = "Global Change Master Directory (GCMD) Earth Science Keywords; CF Standard Name Table (v23, 23 March 2013)";
  :keywords = "Oceans > Ocean Waves > Wave Frequency, Oceans > Ocean Waves > Wave Height, Oceans > Ocean Waves > Wave Period, Oceans > Ocean Waves > Wave Spectra, Oceans > Ocean Waves > Wave Direction, DOD > DOD/USARMY/USACE/CHL/FRF > Field Research Facility, Coastal And Hydraulics Laboratory,U. S. Army Corps Of Engineers, U.S. Army, U. S. Department Of Defense, sea_surface_wave_variance_spectral_density, sea_surface_wave_significant_height, sea_surface_wave_from_direction,  sea_surface_wave_directional_variance_spectral_density\"";
  :pprocessing = "realtime";
  :organization = "USACE/CHL/COAB";
  :publisher_url = "http://www.frf.usace.army.mil";
  :infoUrl = "http://frf.usace.army.mil";
  :publisher_email = "frfwebmaster@usace.army.mil";
  :publisher_name = "USACE/CHL/COAB";
  :format_version = "v1.0";
  :institution = "USACE/CHL/COAB";
  :contact = "USACE/CHL/COAB";
  :contact_info = "USACE/CHL/COAB";
  :contact_role = "Owner";
  :contributor_name = "USACE/CHL/COAB";
  :contributor_role = "USACE/CHL/COAB";
  :naming_authority = "FRF";
  :origin = "USACE/CHL/COAB";
  :date_created = "2025-04-01";
  :date_issued = "2025-04-01";
  :acknowledgement = "Data are provided by the Field Research Facility; Coastal Observations and Analysis Branch; US Army Corps of Engineers, Duck, North Carolina.";
  :project = "USACE/COAB observations";
  :id = "FRF-ocean_waves_waverider-26m";
  :pprocessing_level = "L1";
  :geospatial_vertical_units = "m";
  :geospatial_vertical_resolution = 0.0; // double
  :geospatial_vertical_min = 0.0; // double
  :geospatial_vertical_max = 0.0; // double
  :geospatial_vertical_origin = "sea surface";
  :geospatial_lat_min = 36.25768333; // double
  :geospatial_lat_max = 36.25768333; // double
  :geospatial_lat_units = "degrees_north";
  :geospatial_lon_min = -75.59131666; // double
  :geospatial_lon_max = -75.59131666; // double
  :geospatial_lon_units = "degrees_east";
  :geospatial_vertical_positive = "up";
  :time_coverage_start = "2025-03-01T00:00:00";
  :time_coverage_end = "2025-03-31T23:30:00";
  :deployment_start = "2008-05-23T07:55:00Z";
  :platform = "Datawell Waverider buoy";
  :instrument = "Datawell Waverider buoy (Mk III)";
  :cross_shore_angle_units = "degrees";
  :cross_shore_angle_description = "cross shore angle at the USACE FRF site in DUCK, NC, clockwise from true north";
  :cross_shore_angle = 71.8; // double
}