netcdf frf/geomorphology/DEMs/duneLidarDEM/2024/FRF-geomorphology_DEMs_duneLidarDEM_202402.nc {
  dimensions:
    station_name_length = 13;
    errorDimensions = 3;
    time = UNLIMITED;   // (688 currently)
    xFRF = 130;
    yFRF = 500;
  variables:
    char station_name(station_name_length=13);
      :units = ;
      :long_name = "station name";
      :cf_role = "timeseries_id";
      :short_name = "station_name";

    double time(time=688);
      :_FillValue = -999.99; // double
      :units = "seconds since 1970-01-01 00:00:00";
      :standard_name = "time";
      :long_name = "UTC Sample Time";
      :calendar = "gregorian";
      :description = "\'Hourly time stamp for the bare-earth grid.\'\n";
      :short_name = "time";
      :_ChunkSizes = 512U; // uint

    double xFRF(xFRF=130);
      :_FillValue = -999.99; // double
      :units = "m";
      :long_name = "Local FRF Cross-Shore Coordinate Vector";
      :description = "\'1D Array of FRF X-coordinates (cross-shore) used in the mesh to form the grid. Alongshore values used in gridding are found in the correspondingly named array.\'\n";
      :short_name = "Cross Shore";

    double yFRF(yFRF=500);
      :_FillValue = -999.99; // double
      :units = "m";
      :long_name = "Local FRF Along-Shore Coordinate Vector";
      :description = "\'1D Array of FRF Y-coordinates (alongshore) used in the mesh to form the grid. Cross-shore values used in gridding are found in the correspondingly named array.\'\n";
      :short_name = "Along Shore";

    double latitude(yFRF=500, xFRF=130);
      :long_name = "Latitude";
      :description = "\'Array of latitudes in decimal degrees for gridded elevation points. Each point\'s location in latitude, longitude is found at the same indices in the corresponding variables. Each point\'s FRF X-coordinate, FRF Y-coordinate is found at the same indices in the mesh grids generated from xFRF, yFRF. The elevation for each point can be found at the same indices in Elevation.\'\n";
      :short_name = "lat";
      :_FillValue = -999.99; // double
      :units = "m";

    double longitude(yFRF=500, xFRF=130);
      :_FillValue = -999.99; // double
      :units = "m";
      :long_name = "Longitude";
      :description = "\'Array of longitudes in decimal degrees (positive or W) for gridded elevation points. Each longitude\'s corresponding latitude is found at the same indicies in Latitude. Each point\'s FRF X-coordinate, FRF Y-coordinate is found at the same indices in the mesh grids generated from xFRF, yFRF. The elevation for each point can be found at the same indices in Elevation.\'\n";
      :short_name = "lon";

    double elevation(time=688, yFRF=500, xFRF=130);
      :units = "m";
      :long_name = "Bare-Earth Sub-Aerial Beach Elevation";
      :description = "\'Gridded array of bare-earth sub-aerial beach elevations. Data have been filtered to remove water, vegetation, and other non-ground points.   Filtering was performed with an automated filter and DEMs have not been manually reviewed. Each point\'s location in latitude, longitude is found at the same indices in the corresponding variables. Each point\'s FRF X-coordinate, FRF Y-coordinate is found at the same indices in the mesh grids generated from xFRF, yFRF. Quality of data rectification can be evaluated using coregQCFlag\'\n";
      :short_name = "Elevation";
      :_FillValue = -999.99; // double
      :_ChunkSizes = 1U, 500U, 130U; // uint

    double assessmentPlanesOffset(time=688);
      :_FillValue = -999.99; // double
      :units = "m";
      :long_name = "Norm of Assessment Plane Offsets from Co-registration Accuracy Assessment Planes";
      :description = "\'Norm of offsets in the x-, y-, and z-directions from the co-registration accuracy assessment planes in meters. The y-z assessment plane is a support beam on the FRF Pier, centered at approximately 182.33, 516.56, 6.17 (xFRF, yFRF, elevation) and is 0.037 m x 3.24 m x 0.89 m.  The y-z assessment plane is located approximately 449 m from the lidar.  The x-z assessment plane is the front face of the structure immediately to the south of the main FRF building, centered at approximately -33.70, 482.39, 7.96 (xFRF, yFRF, elevation) and is 2.81 m x 0.053 m x 2.40 m. The x-z assessment plane is located approximately 470 m from the lidar. The x-y assessment plane is a portion of the cul-de-sac in the neighborhood to the north of the device, centered at approximately -24.89, 1085.11, 3.25 (xFRF, yFRF, elevation) and is 2.36 m x 4.00 m x 0.043 m. The x-y assessment plane is located approximately 159 m from the lidar. Note that this offset is not indicative of the offset across the entire DEM.  See rotationSigma and translationSigma for the residual standard error in rotation and translation, respectively, from the plane-matching algorithm. Co-registration QC Flag indicates the overall quality of the co-registration. Co-registration Algorithm Flag indicates which alogrithm was used for co-registration.\'\n";
      :short_name = "Norm Assessment Plane Offsets";
      :_ChunkSizes = 1U; // uint

    double rmsReflectorError(time=688);
      :_FillValue = -999.99; // double
      :units = "m";
      :long_name = "Root Mean Square Error in Reflector Centroids";
      :description = "\'Root mean square residual error of the centroids of 4-6 reflectors in scan.  Actual reflector centroid locations were determined from a 3-minute survey using real-time kinematic (RTK) global positioning system (GPS) surveying equipment, with position converted to the local FRF coordinate system. Reflector centroids in scan were found using a reflectance threshold in 1 m cube around surveyed reflector location. See rotationSigma and translationSigma for the residual standard error in rotation and translation, respectively, from the plane-matching algorithm. See assessmentPlanesOffset for the norm of the x-, y-, and z-offsets from the co-registration assessment planes. Co-registration QC Flag indicates the overall quality of the co-registration. Co-registration Algorithm Flag indicates which alogrithm was used for co-registration.\'\n";
      :short_name = "RMS Reflector Error";
      :_ChunkSizes = 1U; // uint

    double translationSigma(time=688, errorDimensions=3);
      :units = ;
      :long_name = "Residual Standard Error in Translation";
      :description = "\'Residual standard error in translation calculated from the least squares fit during plane-matching co-registration with dimensions listed in errorDimension. See rotationSigma for the residual standard error in rotation from plane-matching co-registration. See assessmentPlanesOffset for the norm of the x-, y-, and z-offsets from the co-registration assessment planes. See rmsReflectorError for RMS error of reflector centroids in scan. Co-registration QC Flag indicates the overall quality of the co-registration. Co-registration Algorithm Flag indicates which alogrithm was used for co-registration.\'\n";
      :short_name = "Translation Standard Error";
      :_FillValue = -999.99; // double
      :_ChunkSizes = 1U, 3U; // uint

    double rotationSigma(time=688, errorDimensions=3);
      :description = "\'Residual standard error in rotation calculated from the least squares fit during plane-matching co-registration with dimensions listed in errorDimension. See translationSigma for the residual standard error in translation from plane-matching co-registration. See assessmentPlanesOffset for the norm of the x-, y-, and z-offsets from the co-registration assessment planes. See rmsReflectorError for RMS error of reflector centroids in scan. Co-registration QC Flag indicates the overall quality of the co-registration. Co-registration Algorithm Flag indicates which alogrithm was used for co-registration.\'\n";
      :short_name = "Rotation Standard Error";
      :units = ;
      :long_name = "Residual Standard Error in Rotation";
      :_FillValue = -999.99; // double
      :_ChunkSizes = 1U, 3U; // uint

    double coregQCFlag(time=688);
      :_FillValue = 9.0; // double
      :units = ;
      :long_name = "Coregistration Algorithm QC Flag";
      :flag_values = "1, 2, 3, 4, 9";
      :flag_meanings = "1=good_plane_matching, 2=not_coregistered, 3=questionable_or_non_plane_based, 4=bad, 9=missing";
      :description = "\'Coregistration algorithm quality indicator. This flag should be used to evaluate quality of DEM rectification prior to data use.  Flag 1 indicates co-registration using a plane-matching co-registration algorithm, norm of translationSigma < 0.004 m, norm of the assessment plane offsets < 0.1 m, and the RMS reflector error < 0.1 m. Flag 2 indicates that the original rectification matrix was used (the scan was not co-registered). Flag 3 indicates co-registration using a plane-matching algorithm with a combined translationSigma >= 0.004 m or a different co-registration algorithm used, with the norm of the assessment plane offsets < 0.1 m, and the RMS reflector error < 0.1 m. Flag 4 indicates that the norm of the assessment plane offsets >= 0.1 m or the RMS reflector error >= 0.1 m Flag 9 indicates that the scan was missing or that co-registration was not attempted General flag definitions guided by the Ocean Data Standards, UNESCO 2013 - IOC Manurals and Guides, 54, Volume 3 Version 1.\'\n";
      :short_name = "Coregistration QC Flag";
      :_ChunkSizes = 1U; // uint

    double coregAlgorithmFlag(time=688);
      :_FillValue = 9.0; // double
      :units = ;
      :long_name = "Coregistration Algorithm Indicator Flag";
      :flag_values = "1, 2, 3, 4, 5, 6, 9";
      :flag_meanings = "1=plane_matching, 2=rectififcation_only, 3=recent_coregistration_matrix, 4=four_reflector_centroids, 5=five_reflector_centroids, 6=six_reflector_centroids, 9=missing";
      :description = "\'Coregistration algorithm type indicator. See coregQCFlag for indication of overall coregistration quality and rotationSigms/translationSigma for plane-matching coregistration quality. Flag 1 indicates co-registration using a plane-matching co-registration algorithm. Flag 2 indicates no co-registration, using only the appropriate rectification matrix. Flag 3 indicates co-registration using a recent scan\'s coregistration matrix, within 12 hours before scan or 6 hours since scan. Flag 4 indicates co-registration using reflector centroids of the closest four reflectors, exclude the furthest reflector. Flag 5 indicates co-registration using reflector centroids of five reflectors. Flag 6 indicates co-registration using reflector centroids of six reflectors. Flag 9 indicates no co-registration attempted.\'\n";
      :short_name = "Coregistration Algorithm Flag";
      :_ChunkSizes = 1U; // uint

  // global attributes:
  :title = "lidarBeachDEM";
  :name = "VZ-1000 Calculated Beach Digital Elevation Model";
  :featureType = "grid";
  :summary = "Digital Elevation model collected using a Riegl VZ-1000 or VZ-2000 terrestrial laser scanner mounted on the North lidar tower at the United States Armp Corps of Engineers\' Coastal And Hydraulics Laboratory\'s Field Research Facility (USACE/CHL/FRF) in Duck, NC. The Riegl VZ-1000 is the primary data collection instrument, with the VZ-2000 deployed while the VZ-1000 is being serviced.";
  :description = "Lidar Beach Digital Elevation Model";
  :comment = "Lidar point density and accuracy decreases with range. Please check coregQCFlag for a measure of rectification accuracy.";
  :cdm_data_type = "Station";
  :history = "Measured, rectified, coregistered, and processed at USACE/CHL/FRF.";
  :source = "VZ-1000 or VZ-2000 terrestrial laser scanner observations from the North lidar tower at USACE/CHL/FRF.";
  :sourceUrl = "(local files)";
  :standard_name_vocabulary = "CFv25";
  :Metadata_Conventions = "Unidata Dataset Discovery v1.0, CF-1.6";
  :Conventions = "CF-1.6";
  :creator_name = "USACE/CHL/FRF";
  :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 = "CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > NORTH CAROLINA, EARTH SCIENCE > OCEANS > COASTAL PROCESSES,  EARTH SCIENCE > OCEANS > COASTAL PROCESSES > BEACHES, EARTH SCIENCE > OCEANS > COASTAL PROCESSES > INTERTIDAL ZONE, EARTH SCIENCE > OCEANS > COASTAL PROCESSES > SHORELINES, EARTH SCIENCE > OCEANS > OCEAN WAVES, Earth Remote Sensing Instruments > Active Remote Sensing > Altimeters > Lidar/Laser Altimeters 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,\n Lidar Data\n";
  :processing = "realtime";
  :organization = "USACE/CHL/FRF";
  :publisher_url = "http://www.frf.usace.army.mil";
  :infoUrl = "http://chlthredds.erdc.dren.mil/thredds/catalog/frf/catalog.html";
  :publisher_email = "frfwebmaster@usace.army.mil";
  :publisher_name = "USACE/CHL/FRF";
  :format_version = "v1.0";
  :institution = "U. S. Army Corps Of Engineers, Coastal And Hydraulics Laboratory,  Field Research Facility (USACE/CHL/FRF)";
  :contact = "USACE/CHL/FRF";
  :contact_info = "USACE/CHL/FRF";
  :contact_role = "owner";
  :contributor_name = "USACE/CHL/FRF";
  :contributor_role = "USACE/CHL/FRF";
  :naming_authority = "FRF";
  :origin = "USACE/CHL/FRF";
  :acknowledgement = "Data are provided by the US Army Engineer Research & Development Center, Coastal and Hydrualics Laboratory\'s Field Research Facility in Duck, NC.";
  :project = "USACE Coastal Field Data Collection Program";
  :id = 948.0; // double
  :processing_level = "L1";
  :geospatial_vertical_units = "m";
  :geospatial_vertical_resolution = 0.01; // double
  :geospatial_vertical_min = -5.0; // double
  :geospatial_vertical_max = 10.0; // double
  :geospatial_vertical_origin = "NAVD88 (geoid12b)";
  :geospatial_lat_min = 36.17906247087372; // double
  :geospatial_lat_max = 36.18251249185555; // double
  :geospatial_lat_units = "degrees_north";
  :geospatial_lon_min = -75.73714264268493; // double
  :geospatial_lon_max = -75.746085545176; // double
  :geospatial_lon_units = "degrees_east";
  :geospatial_vertical_positive = "up";
  :time_coverage_start = "2024-02-01T00:30:16";
  :deployment_start = "2015-01-15T15:20:00Z";
  :deployment_end = ; // double
  :platform = "North lidar tower";
  :instrument = "Riegl VZ-1000 or VZ-2000 terrestrial laser scanner";
  :vertical_datum = "NAVD88 (geoid12b)";
  :horizontal_datum = "FRF coordinates (rotated from NAD83(2011), North Carolina State Plane, meters(3200) using origin [901951.6805 E, 274093.1562 N] and rotation angle 69.9747)";
  :depth = 0.0; // double
  :date_created = "2024-02-29";
  :date_issued = "2024-02-29";
  :time_coverage_end = "2024-02-29T23:41:13";
}