netcdf frf/oceanography/waves/awac-6m/awac-6m.ncml { dimensions: station_name_length = 17; waveFrequency = 62; waveDirectionBins = 72; time = 102625; variables: char station_name(station_name_length=17); :units = ; :long_name = "station name"; :cf_role = "timeseries_id"; :short_name = "station_name"; :_ChunkSizes = 17U; // 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 gaugeElevation; :description = "Gauge Vertical Position from NAVD88"; :long_name = "Gauge Elevation"; :short_name = "Gauge Elevation"; :_FillValue = -999.0f; // float :units = "m"; 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 :long_name = "Band Center in Degrees"; :short_name = "Direction"; :units = "degree"; :_ChunkSizes = 72U; // uint double time(time=102625); :_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 = 745U; // uint float depth(time=102625); :_FillValue = -999.0f; // float :units = "m"; :long_name = "Water Depth"; :standard_name = "sea_floor_depth_below_sea_surface"; :short_name = "Depth"; :_ChunkSizes = 745U; // uint float waveHs(time=102625); :_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 = 745U; // uint float waveTp(time=102625); :_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 = 745U; // uint float waveTpfb(time=102625); :_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 = 745U; // uint float waveTm(time=102625); :_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 = 745U; // uint float waveTm1(time=102625); :_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 = 745U; // uint float waveTm2(time=102625); :_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 = 745U; // uint float wavePeakDirectionPeakFrequency(time=102625); :_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 = 745U; // uint float waveMeanDirection(time=102625); :_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 = 745U; // uint float waveMeanDirectionPeakFrequency(time=102625); :_FillValue = -999.0f; // float :units = "degree"; :description = "Wave direction is from true north (MET convention), energy weighted at peak frequency"; :long_name = "Wave Wean Direction at the Peak Frequency"; :coordinates = "lat lon"; :short_name = "thetaMp"; :_ChunkSizes = 745U; // uint float wavePrincipleDirection(time=102625); :_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 Primciple Direction of 2D Spectrum"; :coordinates = "lat lon"; :short_name = "thetaM2"; :_ChunkSizes = 745U; // uint float waveEnergyDensity(time=102625, 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 = 745U, 62U; // uint float directionalWaveEnergyDensity(time=102625, 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 float depthElevation(time=102625); :_FillValue = -999.0f; // float :units = "m"; :description = "Bottom vertical location from NAVD88 computed from the surveyed gauge depth and gauge height off the bottom based on altimeter or survey data, or nominal data. See depthSource."; :long_name = "Bottom Elevation (NAVD88)"; :short_name = "Bottom Elevation"; :_ChunkSizes = 745U; // uint byte depthSource(time=102625); :_FillValue = -99B; // byte :units = ; :long_name = "Flag of how bottom location was determined (0=nominal depth, 1=altimeter, 2=bathymetric survey)"; :short_name = "BottomZ"; :coordinates = "lat lon"; :_ChunkSizes = 745U; // uint byte qcFlagE(time=102625); :_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 = 745U; // uint byte qcFlagD(time=102625); :_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 = 745U; // uint float directionalPeakSpread(time=102625); :_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 = 745U; // uint float spectralWidthParameter(time=102625); :_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 = 745U; // uint byte waveDirectionEstimator(time=102625); :_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 = 745U; // uint float waveA1Value(time=102625, waveFrequency=62); :_FillValue = -999.0f; // float :units = ; :description = "a1 Fourier coefficient"; :long_name = "a1 Directional Fourier Coefficient"; :coordinates = "lat lon"; :short_name = "a1"; :_ChunkSizes = 745U, 62U; // uint float waveB1Value(time=102625, waveFrequency=62); :_FillValue = -999.0f; // float :units = ; :description = "b1 Fourier coefficient"; :long_name = "b1 Directional Fourier Coefficient"; :coordinates = "lat lon"; :short_name = "b1"; :_ChunkSizes = 745U, 62U; // uint float waveA2Value(time=102625, waveFrequency=62); :_FillValue = -999.0f; // float :units = ; :description = "a2 Fourier coefficient"; :long_name = "a2 Directional Fourier Coefficient"; :coordinates = "lat lon"; :short_name = "a2"; :_ChunkSizes = 745U, 62U; // uint float waveB2Value(time=102625, waveFrequency=62); :_FillValue = -999.0f; // float :units = ; :description = "b2 Fourier coefficient"; :long_name = "b2 Directional Fourier Coefficient"; :coordinates = "lat lon"; :short_name = "b2"; :_ChunkSizes = 745U, 62U; // uint float waterLevel(time=102625); :_FillValue = -999.0f; // float :units = "m"; :standard_name = "water_surface_height_above_reference_datum"; :long_name = "Water Level Height"; :description = "Water level based on sensor mean pressure and surveyed location of sensor (NAVD88), barometrically corrected, see mbar value"; :short_name = "Water Level"; :coordinates = "time lat lon"; :_ChunkSizes = 745U; // uint float airPressure(time=102625); :_FillValue = -999.0f; // float :units = "mbar"; :standard_name = "air_pressure"; :long_name = "Barometric Pressure"; :description = "Atmospheric pressure at sea level measured with a shore based sensor, averaged over wave record"; :short_name = "Barom Pressure"; :coordinates = "time lat lon"; :_ChunkSizes = 745U; // uint // global attributes: :featureType = "timeSeries"; :title = "FRF 6m AWAC Waves"; :station_name = "6m-AWAC"; :summary = "USACE/COAB data collected by a bottom mounted (looking up) Nortek AWAC, approximately 550m offshore of Duck (FRF), NC at a nominal depth of 6m NAVD88. Directional spectra are computed using a custom COAB analysis of merging low frequency AST-UV (or PUV) spectra with high-end beam-array spectra (see http link frf.usace.army.mil/realtime/awac/COAB_awacSpectralAnalysis.pdf). Data collection is hard-wired and analyzed hourly with 34 minute timeseries records. Two dimensional frequency-direction spectra are computed using a Maximum Likelihood Estimator (MLE) method. The Fourier coefficients were estimated from the 2D spectra. A description of computing these coefficients is provided in Use of advanced directional wave spectra analysis methods, M. D. Earle, K. E. Steele, and D. W. C. Wang, Ocean Engineering, Volume 26, Issue 12, December 1999, Pages 1421-1434. Or Kuik et. al, JPO, 18, pp. 1020-1034, 1988.\n"; :history = "2015-09-19:data set created"; :source = "In situ observations from FRF-ocean_waves_awac-6m_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://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""; :processing = "historical"; :organization = "USACE/CHL/COAB"; :publisher_url = "http://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 = "2023-03-31"; :date_issued = "2023-03-31"; :acknowledgement = "Data are provided by the Field Research Facility; Coastal Observations & Analysis Branch; US Army Corps of Engineers, Duck, North Carolina."; :project = "USACE/COAB observations"; :id = "FRF-ocean_waves_awac-6m"; :processing_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 = "NAVD88"; :geospatial_lat_min = 36.1873342; // double :geospatial_lat_max = 36.1873342; // double :geospatial_lat_units = "degrees_north"; :geospatial_lon_min = -75.7465382; // double :geospatial_lon_max = -75.7465382; // double :geospatial_lon_units = "degrees_east"; :geospatial_vertical_positive = "up"; :xducerDepth = 5.66; // double :nomDepth = 6.5; // double :time_coverage_start = "2023-03-01T00:00:03"; :time_coverage_end = "2023-04-01T00:00:03"; :deployment_start = "2015-09-18T22:00:00Z"; :platform = "Nortek AWAC"; :instrument = "Nortek AWAC"; :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 }