Benthic Habitat Mapping - Dry Tortugas RoxAnn Acoustic Sensor Data Points (NODC Accession 0001045)

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

Frequently anticipated questions:


What does this data set describe?

Title:
Benthic Habitat Mapping - Dry Tortugas RoxAnn Acoustic Sensor Data Points (NODC Accession 0001045)
Abstract:
During April 2001 RoxAnn single-beam acoustic surveys were conducted at the North Unit of the Tortugas Ecological Reserve, Florida. Thirteen transects associated with fixed bottom sampling stations were surveyed to characterize the ecotone around the stations. In addition survey tracks were run along the outer edge of the Tortugas platform reef complex and into the interior of the platform. A towed video sled (minibat) was deployed simultaneously with the RoxAnn survey which provided a live video ground truth to the acoustic signals. Using this ground truth several bottom classes were identified including coral, seagrass, algae, unconsolidated sediments, and hardbottoms. The original RoxAnn categories are preserved in the Class field and benthic habitat codes from the Florida System for Classifying Estuarine and Marine Environments (SCHEME) system are preserved in the SCHEME field. The depth value is in meters below transducer surface.
  1. How should this data set be cited?

    Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC), 20050801, Benthic Habitat Mapping - Dry Tortugas RoxAnn Acoustic Sensor Data Points (NODC Accession 0001045): NOAA's Ocean Service, Coastal Services Center (CSC), Charleston, SC.

    Online Links:

    This is part of the following larger work.

    Laboratory, NOAA Beaufort , 20040401, Biogeographic Analysis of the Tortugas Ecological Reserve Examining the Refuge Effect Following Reserve Establishment: Marine Sanctuaries Division, Silver Spring, MD.

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -83.0003
    East_Bounding_Coordinate: -82.7618
    North_Bounding_Coordinate: 24.7391
    South_Bounding_Coordinate: 24.5195

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 08-Apr-2001
    Ending_Date: 12-Apr-2001
    Currentness_Reference: Ground Condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: Map

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Point data set. It contains the following vector data types (SDTS terminology):

      • Point (25933)

    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: -81.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000

      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 1
      Ordinates (y-coordinates) are specified to the nearest 1
      Planar coordinates are specified in unknown. Abscissa/Ordinate Resolution values were unreported and populated with one to satisfy validation requirements

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is GRS 80.
      The semi-major axis of the ellipsoid used is 6378137.0000000.
      The flattening of the ellipsoid used is 1/298.26.

  7. How does the data set describe geographic features?

    fl_dt01.dbf
    Shapefile Attribute Table (Source: None)

    Class
    Unknown (Source: Unknown)

    Range of values
    Minimum:0
    Maximum:30

    Latitude
    Unknown (Source: Unknown)

    Range of values
    Minimum:24.52
    Maximum:24.7381

    Longitude
    Unknown (Source: Unknown)

    Range of values
    Minimum:-82.9984
    Maximum:-82.7639

    Depth
    Unknown (Source: Unknown)

    Range of values
    Minimum:-35.55
    Maximum:-5.59

    E1
    Unknown (Source: Unknown)

    Range of values
    Minimum:0.029
    Maximum:2.64

    E2
    Unknown (Source: Unknown)

    Range of values
    Minimum:0.02
    Maximum:1.289

    Time
    Unknown (Source: Unknown)

    Eastern Daylight Time

    Date_
    Unknown (Source: Unknown)

    Date

    Scheme
    Unknown (Source: Unknown)

    Range of values
    Minimum:3
    Maximum:342

    Modifier
    Unknown (Source: Unknown)

    SCHEME Modifier

    Habitat
    Unknown (Source: Unknown)

    Habitat Description


Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    NOAA Coastal Services Center
    2234 South Hobson Avenue
    Charleston, South Carolina 29405
    USA

    (843) 740-1264 (voice)
    (843) 740-1289 (FAX)

    Hours_of_Service: 8:00 - 17:00 EST


Why was the data set created?

The single-beam surveys were part of a larger biogeographic characterization effort intended to characterize benthic habitats, ocean circulation patterns, in the newly established Tortugas Ecological Reserve. The goal of the project was to establish a baseline of environmental conditions and processes that could be compared to future surveys. This would support evaluations of various reserve managment strategies.


How was the data set created?

  1. From what previous works were the data drawn?

    NOAA CSC (source 1 of 1)
    Department of Commerce (DOC), National Oceanic and Atmospheric Administration (NOAA), National Ocean Service (NOS), Coastal Services Center (CSC), 20050801, Dry Tortugas RoxAnn Points: NOAA's Ocean Service, Coastal Services Center (CSC), Charleston, SC.

    Online Links:

    This is part of the following larger work.

    Laboratory, NOAA Beaufort , 20040401, Biogeographic Analysis of the Tortugas Ecological Reserve Examining the Refuge Effect Following Reserve Establishment: NOAA Marine Sanctuaries Division, Silver Spring, MD.

    Type_of_Source_Media: map
    Source_Contribution: Unknown

  2. How were the data generated, processed, and modified?

    Date: Apr-2001 (process 1 of 2)
    Between 8 and 12 April 2001 RoxAnn single-beam acoustic data were collected along 16 transects running across the edge of the Tortugas platform reef. The transducer was mounted on a pole attached to the side of the research vessel and was co-located with a PLGR GPS unit. Data were recorded at 1 second intervals. The E1 and E2 signals received were displayed and logged in the normal RoxMap Scientific software environment. The vessel speed during collection was approximately 4 kts. Simultaneous to collection of the acoustic data a towed video sled was deployed astern of the ship. The picture from this video was displayed in the lab within view of the RoxAnn data analyst. This allowed a near real-time reference for the acoustic data. This ground-truth was used to assign the RoxAnn soundings into several bottom classes. At the conclusion of each transect run. The instrument was shut off until the next transect was visited.

    Person who carried out this activity:

    NOAA Coastal Services Center
    2234 South Hobson Avenue
    Charleston, South Carolina 20405
    USA

    (843) 740-1264 (voice)
    (843) 740-1289 (FAX)
    clearinghouse@noaa.gov

    Hours_of_Service: 08:00 - 17:00 EST
    Date: 01-Dec-2003 (process 2 of 2)
    The full RoxAnn record collected during the April cruise was exported from the RoxMap environment and converted into ESRI shapefile format for further analysis. A set of tools developed at CSC specifically for cleaning RoxAnn data were used to remove noise and anomalous points from the record. These points included spikes and pits in the bathymetry as well as bad data caused by surface turbulence. Each bottom class in the data was then exported individually and displayed on a scatterplot of E1 vs. E2 values to examine its geometry. The cluster means (E1 and E2) for each class were also displayed relative to each other as a logical check between classes. The final results were recoded into the Florida SCHEME benthic habitat classification system to ensure consistency with other CSC benthic data.

    Person who carried out this activity:

    NOAA Coastal Services Center
    2234 South Hobson Avenue
    Charleston, South Carolina 20405
    USA

    (843) 740-1264 (voice)
    (843) 740-1289 (FAX)
    clearinghouse@noaa.gov

    Hours_of_Service: 08:00 - 17:00 EST
  3. What similar or related data should the user be aware of?


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

  1. How well have the observations been checked?

    This data is accurate to field conditions in April 2001. The depth readings have not been corrected for tide stage or wind variables. A towed video system (mini-bat) was deployed behind the vessel where the acoustic transducer was deployed. This provided real-time ground-truth to the acoustic signals. As habitat boundaries were crossed, the RoxAnn acoustic signature box was updated and checked. In addition dive observations were made along the transects to verify the habitat classes.

  2. How accurate are the geographic locations?

    The horizontal positional accuracy is based on the accuracy of the GPS used to generate the coordinate pair for each acoustic record. The GPS unit was a military grade receiver enabled to receive encrypted Y-code from the GPS satellites. his typically produces a spatial accuracy of 10 meters or less.

  3. How accurate are the heights or depths?

    Depth value is in meters below transducer. No correction has been applied for wind or tide effects. No validation was performed on this data and no accuracy is implied.

  4. Where are the gaps in the data? What is missing?

    The data is complete.

  5. How consistent are the relationships among the observations, including topology?

    These data are believed to be logically consistent, though no tests have been performed. Point geometry is topologically clean.


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:
Bathymetric data have not been corrected for tide and wind variables. Not for use in navigation.

  1. Who distributes the data set? (Distributor 1 of 1)

    NOAA Coastal Services Center
    Clearinghouse Manager
    2234 South Hobson Avenue
    Charleston, South Carolina 29405
    USA

    (843) 740-1264 (voice)
    (843 740-1289 (FAX)
    clearinghouse@noaa.gov

    Hours_of_Service: 08:00 - 17:00 EST
  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    Single-beam acoustic data points collected in the Dry Tortugas area of Florida. While every effort has been made to ensure that these data are accurate and reliable within limits of the state of the art, NOAA will not assume any liability for damages caused by any inaccuracies in these data, or failure in their use.

  4. How can I download or order the data?


Who wrote the metadata?

Dates:
Last modified: 03-Sep-2013
Metadata author:
NOAA Coastal Services Center
Metadata Specialist
2234 South Hobson Avenue
Charleston, South Carolina 29405
USA

(843) 740-1210 (voice)
clearinghouse@noaa.gov

Hours_of_Service: 08:00 - 17:00 EST
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)


Generated by mp version 2.9.13 on Thu Jul 24 10:41:27 2014