Seafloor Elevation Change From 2016 to 2017 at Crocker Reef, Florida Keys-Impacts From Hurricane Irma

Metadata also available as - [Outline] - [Parseable text] - [XML]

Frequently anticipated questions:

What does this data set describe?

Title:
Seafloor Elevation Change From 2016 to 2017 at Crocker Reef, Florida Keys-Impacts From Hurricane Irma
Abstract:
The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify bathymetric changes at Crocker Reef near Islamorada, Florida (FL), within a 33.6 square-kilometer area following the landfall of Hurricane Irma in September 2017. USGS staff used light detection and ranging (lidar)-derived data acquired by the National Oceanic and Atmospheric Administration (NOAA) between July 21 and November 21, 2016 and USGS multibeam data collected between October 10 and December 8, 2017 (Fredericks and others, 2019) to assess changes in seafloor elevation and structure that occurred after the passage of Hurricane Irma. An elevation change analysis between the 2016 NOAA lidar data and the 2017 multibeam data was performed to quantify and map impacts to seafloor elevations and to determine elevation and volume change statistics for nine habitat types found at Crocker Reef, FL. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068.
Supplemental_Information:
The lidar data were collected by NOAA National Geodetic Survey (NGS) Remote Sensing Division using a Riegl VQ820G system. The lidar data are an ancillary product of NOAA's Coastal Mapping Program (CMP), created through a wider Integrated Ocean and Coastal Mapping initiative to increase support for multiple uses of the data. The multibeam bathymetry data were collected using two Teledyne SeaBat T50-P multibeam echosounders, in a dual head configuration. Data were collected under Florida Keys National Marine Sanctuary permit FKNMS-2016-068.
  1. How might this data set be cited?
    Yates, Kimberly K., Zawada, David G., Arsenault, Stephanie R., and Fehr, Zachery W., 20190801, Seafloor Elevation Change From 2016 to 2017 at Crocker Reef, Florida Keys-Impacts From Hurricane Irma: U.S. Geological Survey Data Release doi:10.5066/P9JI465S, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

    This is part of the following larger work.

    Yates, Kimberly K., Zawada, David G., Smiley, Nathan A., and Tiling-Range, Ginger, 20170420, Divergence of seafloor elevation and sea level rise in coral reef ecosystems: Biogeosciences, Munich, Germany.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -80.586875
    East_Bounding_Coordinate: -80.500711
    North_Bounding_Coordinate: 24.954833
    South_Bounding_Coordinate: 24.885565
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 21-Jul-2016
    Ending_Date: 08-Dec-2017
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Multimedia presentation
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Vector data set. It contains the following vector data types (SDTS terminology):
      • Entity Point (8402223)
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 17
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -81.0
      Latitude_of_Projection_Origin: 0.0
      False_Easting: 500000.0
      False_Northing: 0.0
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.6096
      Ordinates (y-coordinates) are specified to the nearest 0.6096
      Planar coordinates are specified in METERS
      The horizontal datum used is North American Datum of 1983 National Spatial Reference System (2007).
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Vertical Datum of 1988 (NAVD88) GEOID12B
      Altitude_Resolution: 0.2
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    CrockerReef_Elevation_Statistics.csv
    Crocker Reef elevation change statistics per habitat type from 2016 to 2017. (Source: USGS)
    Habitat types in Crocker Reef study site
    The habitat types found in the Crocker Reef study site. Habitat types are defined by the Unified Florida Reef Tract Map Version 2.0 and based on the Unified Classification (UC) system Class Level 2. (Source: Florida Fish and Wildlife Conservation Commission (FWC))
    ValueDefinition
    Total study siteThe total Crocker Reef study site, includes 9 habitat types.
    Aggregate reefAggregate reef larger than 1 hectare (ha), contiguous reef, lacking sand channels.
    Individual or aggregated patch reefPatch reefs smaller than 1 ha, isolated reefs often with distinct halo or reef features covering >10% of the area.
    PavementContiguous to patchy pavement, lacking spur and groove channel formations.
    Pavement with sand channelsAlternating linear sand and pavement formations, perpendicular to reef crest.
    Reef rubbleUnconsolidated, dead, unstable coral rubble.
    Scattered rock or coral in unconsolidated sedimentLess than 150 square meters, mostly sand, reef features covering <10% of the area.
    Seagrass continuousContinuous seagrass beds.
    Seagrass discontinuousDiscontinuous seagrass beds.
    Unconsolidated sedimentUnconsolidated sediment
    Total points (no.)
    The total number of points within or on the boundary of each Crocker Reef habitat type. (Source: USGS)
    Range of values
    Minimum:10997
    Maximum:8402223
    Units:number of points
    Mean elevation change (m)
    Mean elevation change per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:0.25454
    Maximum:0.615626
    Units:meters
    Mean elevation change SD (m)
    Standard deviation of the mean elevation change, in meters. (Source: USGS)
    Range of values
    Minimum:0.07704
    Maximum:0.329939
    Units:meters
    Accretion points (no.)
    The total number of accretion points within or on the boundary of each Crocker Reef habitat type. (Source: USGS)
    Range of values
    Minimum:10620
    Maximum:8289476
    Units:number of points
    Max accretion (m)
    Maximum accretion per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:1.166664
    Maximum:4.712902
    Units:meters
    Min accretion (m)
    Minimum accretion per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:0.00053
    Units:meters
    Mean accretion (m)
    Mean accretion per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:0.26675
    Maximum:0.63076
    Units:meters
    Mean accretion SD (m)
    Standard deviation of the mean accretion, in meters. (Source: USGS)
    Range of values
    Minimum:0.067112
    Maximum:0.298326
    Units:meters
    Erosion points (no.)
    The total number of erosion points within or on the boundary of each Crocker Reef habitat type. (Source: USGS)
    Range of values
    Minimum:21
    Maximum:112747
    Units:number of points
    Max erosion (m)
    Maximum erosion per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:-3.459069
    Maximum:-0.125343
    Units:meters
    Min erosion (m)
    Minimum erosion per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:-0.000203
    Maximum:-0.000001
    Units:meters
    Mean erosion (m)
    Mean erosion per habitat type in the Crocker Reef study site from 2016 to 2017, in meters. (Source: USGS)
    Range of values
    Minimum:-0.380553
    Maximum:-0.030589
    Units:meters
    Mean erosion SD (m)
    Standard deviation of the mean erosion, in meters. (Source: USGS)
    Range of values
    Minimum:0.028252
    Maximum:0.402278
    Units:meters
    CrockerReef_Volume_Statistics.csv
    Volume statistics by habitat type in Crocker Reef from 2016 to 2017. (Source: USGS)
    Habitat types in Crocker Reef study site
    The habitat types found in Crocker Reef. Habitat types are defined by the Unified Florida Reef Tract Map Version 2.0 and based on the Unified Classification (UC) system Class Level 2. (Source: FWC)
    ValueDefinition
    Total study siteThe total Crocker Reef study site, includes 9 habitat types.
    Aggregate reefAggregate reef larger than 1 hectare (ha), contiguous reef, lacking sand channels.
    Individual or aggregated patch reefPatch reefs smaller than 1 ha, isolated reefs often with distinct halo or reef features covering >10% of the area.
    PavementContiguous to patchy pavement, lacking spur and groove channel formations.
    Pavement with sand channelsAlternating linear sand and pavement formations, perpendicular to reef crest.
    Reef rubbleUnconsolidated, dead, unstable coral rubble.
    Scattered coral or rock in unconsolidated sedimentLess than 150 square meters, mostly sand, reef features covering <10% of the area.
    Seagrass continuousContinuous seagrass beds.
    Seagrass discontinuousDiscontinuous seagrass beds.
    Unconsolidated sedimentUnconsolidated sediment
    Habitat area (km^2)
    Habitat area, in kilometers squared. (Source: USGS)
    Range of values
    Minimum:0.0437
    Maximum:33.5821
    Units:km^2
    Net erosion lower limit (10^6 m^3)
    Net erosion minimum volume per habitat, in millions of cubic meters. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:0.0090
    Units:10^6 m^3
    Net erosion upper limit (10^6 m^3)
    Net erosion maximum volume per habitat, in millions of cubic meters. (Source: USGS)
    Range of values
    Minimum:0
    Maximum:0.0452
    Units:10^6 m^3
    Net accretion lower limit (10^6 m^3)
    Net accretion minimum volume per habitat, in millions of cubic meters. (Source: USGS)
    Range of values
    Minimum:0.0031
    Maximum:3.9777
    Units:10^6 m^3
    Net accretion upper limit (10^6 m^3)
    Net accretion maximum value per habitat, in millions of cubic meters. (Source: USGS)
    Range of values
    Minimum:0.0113
    Maximum:10.7877
    Units:10^6 m^3
    Net volume change lower limit (10^6 m^3 study area^-1)
    Net volume change lower limit per habitat, in millions of cubic meters per study area. (Source: USGS)
    Range of values
    Minimum:0.0031
    Maximum:3.9687
    Units:10^6 m^3 study area^-1
    Net volume change upper limit (10^6 m^3 study area^-1)
    Net volume change upper limit per habitat, in millions of cubic meters per study area. (Source: USGS)
    Range of values
    Minimum:0.0112
    Maximum:10.7425
    Units:10^6 m^3 study area^-1
    Area normalized volume change lower limit (10^6 m^3 km^-2)
    Area normalized volume change lower limit per habitat, in millions of cubic meters per kilometer squared. (Source: USGS)
    Range of values
    Minimum:0.0709
    Maximum:0.4080
    Units:10^6 m^3 km^-2
    Area normalized volume change upper limit (10^6 m^3 km^-2)
    Area normalized volume change upper limit per habitat, in millions of cubic meters per kilometer squared. (Source: USGS)
    Range of values
    Minimum:0.2563
    Maximum:0.6151
    Units:10^6 m^3 km^-2

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Kimberly K. Yates
    • David G. Zawada
    • Stephanie R. Arsenault
    • Zachery W. Fehr
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Kimberly K. Yates
    Southeast Region: ST. PETE COASTAL & MARINE SCIENCE CENTER
    Research Oceanographer
    600 4Th Street South
    St. Petersburg, FL
    United States

    727-502-8059 (voice)
    kyates@usgs.gov

Why was the data set created?

These data were used to determine seafloor elevation and volume changes, from 2016 to 2017, in Crocker Reef, FL.

How was the data set created?

  1. From what previous works were the data drawn?
    2016 Crocker Reef lidar (source 1 of 3)
    National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), National Geodetic Survey (NGS), Remote Sensing Division, 20170614, 2016 NOAA NGS Topobathy Lidar DEM: Florida Keys Outer Reef Block 02: National Oceanic and Atmospheric Administration, Charleston, SC.

    Online Links:

    Type_of_Source_Media: topobathy data
    Source_Contribution:
    The original lidar data used to calculate elevation and volume change statistics for Crocker Reef from 2016 to 2017.
    2017 Crocker Reef multibeam (source 2 of 3)
    Jake J. Fredericks, Billy J. Reynolds, Andrew S. Farmer, Kimberly K. Yates, and David G. Zawada, 20190701, Multibeam Bathymetry Data Collected in October and December 2017 at Crocker Reef, the Florida Keys: U.S Geological Survey Data Release doi:10.5066/P9EASN2O, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

    Type_of_Source_Media: bathymetry data
    Source_Contribution:
    The original multibeam data used to calculate elevation and volume change statistics for Crocker Reef from 2016 to 2017.
    Habitat file (source 3 of 3)
    Florida Fish and Wildlife Conservation Commission, Fish and Wildlife Research Institute, 20170113, Unified Florida Reef Tract Map Version 2.0: Fish and Wildlife Research Institute, St. Petersburg, FL.

    Online Links:

    Type_of_Source_Media: Vector digital data
    Source_Contribution:
    This shapefile was used to divide the digital elevation model (DEM) by habitat types using Unified Classification (UC) Class Level 2.
  2. How were the data generated, processed, and modified?
    Date: 2019 (process 1 of 11)
    Step 1: The original 2016 NOAA NGS Topography Lidar DEM: Florida Keys Outer Reef Block 02 tagged image file format (TIFF) DEM was downloaded from https://inport.nmfs.noaa.gov/inport/item/49423 using the "Customized Download" capability of NOAA’s DigitalCoast website. The data were downloaded with the following parameters: UTM Zone: Zone 17 Range 084W-078W; Horizontal Datum: NAD83; Horizontal Units: Meters; Vertical Datum: NAVD88; Vertical Units: Meters; File Format: Tiff 32-bit Float; Bin Method: TIN; Bin Size: 1.0; Bin Units: Meters; Data Classification: Bathymetric Lidar Points; Data Returns: Any Points; Ancillary Data: No Ancillary Data; and Geoid Name: GEOID12B. The original 2017 Crocker Reef XYZ multibeam data were downloaded from https://coastal.er.usgs.gov/data-release/doi-P9EASN2O and transformed from their native World Geodetic System of 1984 (WGS84) horizontal datum and ellipsoid heights to the North American Datum of 1983 NAD83(2007) horizontal datum, North American Vertical Datum of 1988 (NAVD88) and applied GEOID12B model using a publicly available software package from NOAA called VDatum version 3.9 (https://vdatum.noaa.gov/). The transformed XYZ points were loaded into Blue Marble Global Mapper version 18.2 and gridded using the "Create Elevation Grid from 2D Vector/Lidar Data" tool in the Analysis menu. Grid spacing was manually set to 1 meter (m) for the X- and Y-axes and the 'Elevation Grid No data Distance Criteria' was set to 3.0. The resultant DEM was exported as a TIFF with the following parameters: 32-bit floating point samples, Sample Spacing of 1 m for both X- and Y-axes, Always Generate Square Pixels, LZW Compression, Generate TFW (World) File, and Generate PRJ File.
    Date: 2019 (process 2 of 11)
    Step 2: Using Esri ArcGIS Desktop Advanced version 10.6, footprints of the original 2016 lidar and 2017 multibeam data were created with the "Reclassify (Spatial Analyst)" tool in ArcToolbox. To create each raster file, all old data values were replaced with 1 and the 'No Data' value with 0 to create the raster files. Then, the "Raster to Polygon (Conversion)" tool was used to create a footprint of the original lidar and original multibeam data by converting the raster files to polygon shape (SHP) files.
    Date: 2019 (process 3 of 11)
    Step 3: A polygon SHP file of the geometric intersection between the lidar and multibeam was created with the "Intersect (Analysis)" tool by adding the lidar and multibeam footprint SHP files (Step 2) as 'Input features', creating the Intersect_footprint SHP file. Then, the lidar and multibeam TIFF's (Step 1) were clipped to the extent of the Intersect_footprint SHP file using the "Clip (Data Management)" tool by specifying the lidar or multibeam TIFF as the 'Input Features' and the Intersect_footprint SHP file as the 'Clip Features', creating the 2016_CrockerReef_Lidar_Clip TIFF and the 2017_CrockerReef_Multibeam_Clip TIFF.
    Date: 2019 (process 4 of 11)
    Step 4: A 2-m grid was created using the "Create Fishnet (Data Management)" tool with the following parameters: Template extent: Intersect_footprint SHP file (Step 3); Cell size width: 2; Cell size height: 2; Number of Rows: left blank, Number of Columns: left blank; Geometry type: POLYLINE and box checked for 'Create Label Points'. The 2m_grid_label SHP file was clipped to the extent of the Intersect_footprint SHP file using the "Clip (Analysis)" tool by specifying the 2m_grid_label SHP file as the 'Input features' and the Intersect_footprint SHP file as the 'Clip features.' XY coordinates were added to the 2m_grid_label SHP file using the "Add XY Coordinates (Data Management)" tool.
    Date: 2019 (process 5 of 11)
    Step 5: Values from the 2016_Lidar_Clip TIFF (Step 3) and 2017_Multibeam_Clip TIFF (Step 3) were extracted at the location of the 2m_grid_label points using the "Extract Values to Points (Spatial Analyst)" tool by specifying the 2m_grid_label SHP file as the 'Input point features' and the 2016_Lidar_Clip TIFF or the 2017_Multibeam_Clip TIFF as the 'Input', creating the Lidar_Extract_Points SHP file and the Multibeam_Extract_Points SHP file. Then, the Lidar_Extract_Points and the Multibeam_Extract_Points SHP files were spatially joined using the "Spatial Join (Analysis)" tool with the following parameters: Target features: Multibeam_Extract_Points; Join features: Lidar_Extract_Points, Join Operation: ONE_TO_ONE and Match Option: Intersect; and Distance field name: left blank.
    Date: 2019 (process 6 of 11)
    Step 6: Points with no data were removed from the 2m_grid_label SHP file using the "Select by Attribute" tool to select points from the attribute table where the RASTERVALU (2017 multibeam) or the RASTERVA_1 (2016 lidar) equaled -9999. Then the "Editor Toolbox" was used to delete the points. The same method was used to remove an additional 970 spurious points (CrockerReef_Lidar_EdgeEffects_Points SHP file) caused by false returns from the lidar, creating the CrockerReef_IntersectPoints SHP file. The elevation difference (Diff_m) between the multibeam and the lidar data were calculated by adding a field to the attribute table of the CrockerReef_IntersectPoints SHP file using the "Field Calculator" and the expression Diff_m = [RASTERVALU]-[RASTERVA_1].
    Date: 2019 (process 7 of 11)
    Step 7: The original Unified Florida Reef Tract Map version 2.0 SHP file was downloaded from http://ocean.floridamarine.org/IntegratedReefMap/UnifiedReefTract.htm. Using Esri ArcGIS, the original habitat SHP file was modified using the "Clip (Analysis)" tool to clip the habitat SHP file to the extent of the Intersect_footprint (Step 3) by specifying the habitat SHP file as the 'Input Features' and the Intersect_footprint SHP file as the 'Clip Features', creating the CrockerReef_Habitat_Clip. Using the "Select by Attribute" tool, individual habitat SHP files were created from the CrockerReef_Habitat_Clip SHP file using the "Select by Attribute" tool to select one ClassLv2 habitat and exporting as a separate SHP file.
    Date: 2019 (process 8 of 11)
    Step 8: Elevation change statistics were determined by habitat type using the XYZ points from the CrockerReef_IntersectPoints SHP file. The "Select Layer by Location (Data Management)" tool was used to extract points within or on the boundary of a specific habitat type by using the following parameters: Input Feature Layer: CrockerReef_IntersectPoints; Relationship: INTERSECT; Selecting Features: Habitat SHP file; Search Distance: left blank; and Selection type: NEW_SELECTION. An ArcMap model was created to automate the process, because these steps had to be repeated for 9 habitat types. Elevation change statistics from Crocker Reef were compiled by habitat type into a comma separated values (CSV) table using Microsoft Excel 2016, see CrockerReef_Elevation_Statistics.csv.
    Date: 2019 (process 9 of 11)
    Step 9: An elevation change surface model was created using the "Create TIN (3D Analyst)" tool by specifying the CrockerReef_IntersectPoints SHP file (Step 6) as the 'Input Feature Class', Diff_m as the 'Height Field' and Mass_Points as the 'Type', creating the Intersect_TIN file. Then, the Intersect_TIN file was delineated using the "Delineate TIN Data Areas (3D Analyst)" tool by specifying the Intersect_TIN as the 'Input TIN', a 'Maximum Edge Length' of 2.828428 (hypotenuse of a 2-m grid) and the 'Method' set to ALL. The delineated Intersect_TIN was clipped to the extent of the Intersect_footprint SHP file (Step 4) using the "Edit TIN (3D Analyst)" tool with the following parameters: Input TIN: Intersect_TIN; Input Features Class: Intersect_footprint SHP file; Height Field: None, Tag Field: None; and Type: Hard clip.
    Date: 2019 (process 10 of 11)
    Step 10: In addition to elevation-change statistics, volume-change statistics per habitat type were calculated using the final TIN (Step 9). Surface volume changes were calculated for four cases using the "Surface Volume (3D Analyst)" tool. To calculate the net erosion lower limit (case 1) the 'Reference Plane' was set to BELOW and the 'Plane Height' set to -0.212 m. For the net erosion upper limit (case 2) the 'Reference Plane' was set to BELOW and the 'Plane Height' set to 0 m. For the net accretion lower limit (case 3) the 'Reference Plane' was set to ABOVE and the 'Plane Height' was set to 0.212 m. For the net accretion upper limit (case 4) the 'Reference Plane' was set to ABOVE and the 'Plane Height' was set to 0 m. A 0.212 m threshold was determined by vertical error analysis using the uncertainties reported in the metadata of the original lidar (0.15 m) and multibeam (0.15m) products to calculate the Root Mean Square Error (RMSE) of 0.212 m. Minimum net volume was calculated by summing results from cases 1 and 3. Maximum net volume was calculated by summing results from cases 2 and 4. Area normalized volume change lower limit was calculated by dividing the minimum net volume change for each habitat by the habitats total area. The area normalized volume change upper limit was calculated by diving the maximum net volume for each habitat by the habitats total area. An ArcMap model was created to automate the process, because these steps had to be repeated for 9 habitat types. Volume change statistics from Crocker Reef were compiled by habitat type in CSV format using Microsoft Excel 2016, see CrockerReef_Volume_Statistics.csv.
    Date: 13-Oct-2020 (process 11 of 11)
    Added keywords section with USGS persistent identifier as theme keyword. Person who carried out this activity:
    U.S. Geological Survey
    Attn: VeeAnn A. Cross
    Marine Geologist
    384 Woods Hole Road
    Woods Hole, MA

    508-548-8700 x2251 (voice)
    508-457-2310 (FAX)
    vatnipp@usgs.gov
  3. What similar or related data should the user be aware of?
    Organization, International Hydrographic, 2008, IHO Standards for Hydrographic Surveys: International Hydrographic Bureau, 4, quai Antoine 1er B.P. 445 - MC 98011 MONACO Cedex Principauté de Monaco.

    Online Links:

    Other_Citation_Details: pages 15-16

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?
    Datasets were visually compared by USGS staff in Esri ArcGIS Desktop Advanced version 10.6 for identification of anomalous elevations or data inconsistencies.
  2. How accurate are the geographic locations?
    For the 2016 lidar, the data positions were obtained using post-processed kinematic global positioning system (KGPS) methods. The horizontal accuracy of the data is better than plus or minus 1.0 meter (m); Quantitative Value: 1.0 m. Multibeam data were collected and processed to meet or exceed International Hydrographic Organization (IHO) Special Order Standards for positioning and depth (IHO, 2008).
  3. How accurate are the heights or depths?
    For the 2016 lidar, the data positions were obtained using post processed KGPS methods. Data used to test the lidar were collected with static GPS observational equipment and compared against the published data. The vertical accuracy of the data is better than plus or minus 0.15 m; Quantitative Value: 0.15 meters. Multibeam data were collected and processed to meet or exceed IHO Special Order Standards for positioning and depth (IHO, 2008).
  4. Where are the gaps in the data? What is missing?
    This dataset is considered complete for the information presented, as described in the abstract section. Users are advised to read the rest of the metadata record and Yates and others (2017) carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    Data cover the area specified for this project, without any known issues.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints: None
Use_Constraints:
Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. The U.S. Geological Survey requests to be acknowledged as originator of these data in future products or derivative research.
  1. Who distributes the data set? (Distributor 1 of 1)
    Kimberly K. Yates
    Southeast Region: ST. PETE COASTAL & MARINE SCIENCE CENTER
    Research Oceanographer
    600 4Th Street South
    St. Petersburg, FL
    United States

    727-502-8059 (voice)
    kyates@usgs.gov
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    Although these data have been processed successfully on a computer system at the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system, or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. The USGS shall not be held liable for improper or incorrect use of the data described or contained herein. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
  4. How can I download or order the data?

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2020
Metadata author:
Kimberly K. Yates
Southeast Region: ST. PETE COASTAL & MARINE SCIENCE CENTER
Research Oceanographer
600 4Th Street South
St. Petersburg, FL
United States

727-502-8059 (voice)
kyates@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/CrockerReef_2016_to_2017_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:18:46 2021