Identification_Information:
  Citation:
    Citation_Information:
      Originator: U. S. Gological Survery
      Publication_Date: 2007
      Title: EAARL Submarine Topography-Florida Keys National Marine Sanctuary
      Edition: First
      Geospatial_Data_Presentation_Form: remote-sensing image
      Series_Information:
        Series_Name: Open File Report
        Issue_Identification: 2007-1395
      Publication_Information:
        Publication_Place: FISC St. Petersburg
        Publisher: U. S. Gological Survery
      Other_Citation_Details: The USGS, in cooperation with the National Aeronautics and Space Administration (NASA), the National Oceani and Atmospheric Administration (NOAA) and the National Park Service (NPS), provides the coastal management community with digital elevation products.  The USGS processes aircraft liar data provided by NASA, develops software tools and algorithms to use and analyze the data, and makes products available to the coastal management community.
  Description:
    Abstract: Lidar is a remote sensing technique that uses laser light to detect, range, or identify remote objects based on light reflected by the object or emitted through its subsequent fluorescence. Airborne ranging Lidar is now being applied in coastal environments to produce accurate, cost-efficient elevation datasets with high spatial density.  The USGS in cooperation with NASA, NOAA, and NPS is using airborne Lidar to measure the submerged topography of the northern Florida reef tract; secondarily, the data will be assessed for its potential in terms of benthic characterization.  Elevation measurements were collected over part of the Florida Keys National Marine Sanctuary (FKNMS) using the NASA Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure subaerial and submarine topography. The system uses a high frequency laser beam directed at the earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The EAARL system, developed by the NASA Wallops Flight Facility (WFF) in Virginia, measures ground elevation with a vertical resolution of roughly 15 centimeters.  A sampling rate of up to 3 kHz results in an extremely dense spatial elevation data set. The EAARL system is typically flown at 300 m altitude AGL, resulting in a 240 m swath for each flightline. Data collection occurred with approximately 50% overlap between flightlines, resulting in about one laser sounding per square meter. The data were processed by the USGS FISC (St. Petersburg office) to produce 1 meter resolution raster images that can be easily ingested into a Geographic Information System (GIS).  The data were organized as 2 km by 2 km data tiles in 32 bit floating-point integer GeoTIFF format.
    Purpose: The objective of this research is the creation of techniques for the surveying of submerged topography for the purposes of habitat mapping, ecological monitoring, change detection, and event assessment (e.g., hurricanes and extreme storm events). As part of this project, data from NASA EAARL were used. This sensor has the potential to make significant contributions in this realm for measuring shallow water depth and conducting cross-environment surveys. High spectral resolution and low costs were found to be key factors in providing accurate and affordable imagery to managers of coastal tropical habitats.
    Supplemental_Information: Raw Lidar data is not in a format that is generally usable by Park Service resource managers and scientists for scientific analysis.  Converting dense Lidar elevation data into a readily usable format without loss of essential information requires specialized processing.  The USGS converts raw Lidar data into a GIS-compatible map product to be provided to NPS GIS specialists, managers, and scientists.  The primary tool used in the conversion process is Airborne Lidar Processing System (ALPS), a multi-tiered processing system developed by a USGS/NASA collaborative project for the generation of subaerial and submarine Lidar topographic products.  Specialized processing algorithms are used to convert raw waveform Lidar data acquired by the EAARL to geo-referenced spot (x,y,z) returns for submarine topography.  These data are then converted to the  North American (Horizontal ) Datum of 1983 (NAD83) and the North American Vertical Datum of 1988 (NAVD88, using the Geoid 03 model).  The final products are 2x2-km map tiles written out in a standard GeoTIFF format with associated metadata information. These tiles are created for visual interpretation and regional quantitative analysis.  Metadata files include the standard FGDC format.
  Time_Period_of_Content:
    Time_Period_Information:
      Multiple_Dates/Times:
        Single_Date/Time:
          Calendar_Date: 20060417
        Single_Date/Time:
          Calendar_Date: 20060418
        Single_Date/Time:
          Calendar_Date: 20060419
        Single_Date/Time:
          Calendar_Date: 20060420
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: As needed
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate:
      East_Bounding_Coordinate:
      North_Bounding_Coordinate:
      South_Bounding_Coordinate:
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: None
      Theme_Keyword: LIDAR, Experimental Advanced Airborne Research Lidar, digital elevation model, elevation change, laser altimetry, derived surface, coastal resource management, Airborne Lidar Processing System, benthic cover types, submarine elevations
    Place:
      Place_Keyword_Thesaurus: None
      Place_Keyword: Florida Keys National Marine Sanctuary
      Place_Keyword: Florida
      Place_Keyword: Florida Keys
      Place_Keyword: United States
    Stratum:
      Stratum_Keyword: submarine topography
  Access_Constraints: Any use of these data signifies a user's agreement to comprehension and compliance of the USGS Standard Disclaimer.  Ensure all portions of metadata are read and clearly understood before using these data in order to protect both user and USGS interests.  See section 6.3 Distribution Liability.
  Use_Constraints:
    Although the USGS is making these data sets available to others who may find the data of value, USGS does not warrant, endorse, or recommend the use of these data for any given purpose.  The user assumes the entire risk related to the use of these data.  These data sets are not for navigational purposes.  USGS is providing these data "as is", and USGS disclaims any and all warranties, whether expressed or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose.  In no event will USGS be liable to you or to any third party for any direct, indirect, incidental, consequential, special, or exemplary damages or lost profits resulting from any use or misuse of these data.

    Acknowledgement of the U.S. Geological Survey, FISC - St. Petersburg as a data source would be appreciated in products developed from these data, and such acknowledgement as is standard for citation and legal practices for data source is expected by users of this data set.  Sharing new data layers developed directly from these data would also be appreciated by USGS staff.  Users should be aware that comparisons with other data sets for the same area from other time periods may be inaccurate due to inconsistencies resulting from changes in photo interpretation, mapping conventions, and digital processes over time.  These data are not legal documents and are not to be used as such.
  Point_of_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U. S. Gological Survery, FISC St. Petersburg
        Contact_Person: Dr. John C. Brock
      Contact_Position: Research Oceanographer
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 600 4th Street South
        City: St. Petersburg
        State_or_Province: Florida
        Postal_Code: 33701
        Country: USA
      Contact_Voice_Telephone: (727) 803-8747 ext3088
      Contact_Facsimile_Telephone: (727) 803-2031
      Contact_Electronic_Mail_Address: jbrock@usgs.gov
      Hours_of_Service: 8am to 5pm M-F EST
  Data_Set_Credit: The U. S. Gological Survery, Florida Integrated Science Center, St. Petersburg would like to acknowledge NASA Goddard Space Flight Center and NOAA National Geodetic Survey - Remote Sensing Division for their cooperation and assistance in the acquisition and processing of the data.  The National Park Service also contributed by cleaning the Lidar dataset in preparation for map production.
  Security_Information:
    Security_Classification: Unclassified
  Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.2.1.1332
  Cross_Reference:
    Citation_Information:
      Originator: Brock, J.C.; Wright, C.W.; Sallenger, A.H; Krabill, W.B., and Swift
      Title: Basis and Methods of NASA Airborne Topographic Mapper Lidar Surveys for Coastal Studies
      Geospatial_Data_Presentation_Form: journal article
      Publication_Information:
        Publication_Place: West Palm Beach, Florida
        Publisher: Journal of Coastal Research
      Larger_Work_Citation:
        Citation_Information:
          Publication_Information:
            Publication_Place: Miami, FL
            Publisher: Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments
  Cross_Reference:
    Citation_Information:
      Originator: Wright, C.W. and Brock, J.C.
      Title: EAARL: A Lidar for mapping shallow coral reefs and other coastal environments
      Geospatial_Data_Presentation_Form: Proceedings Article
      Publication_Information:
        Publication_Place: Miami, FL
        Publisher: Proceedings of the Seventh International Conference on Remote Sensing for Marine and Coastal Environments
  Cross_Reference:
    Citation_Information:
      Originator: John Brock and Asbury Sallenger
      Title: Airborne Topographic Lidar Mapping for Coastal Science and Resource Management
      Geospatial_Data_Presentation_Form: USGS Open File Report
      Publication_Information:
        Publication_Place: St. Petersburg
        Publisher: U.S. Geological Survey
  Cross_Reference:
    Citation_Information:
      Originator: Nayegandhi, A., Brock, J.C., Wright, C.W., OConnell, M.O., 2006
      Title: Evaluating a small-footprint, waveform-resolving Lidar over coastal vegetation communities
      Geospatial_Data_Presentation_Form: USGS Open File Report
      Series_Information:
        Series_Name: 2006-12:1408-1417
      Publication_Information:
        Publisher: Photogrammetric Engineering and Remote Sensing
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: The expected accuracy of the measured variables are as follows: attitude within 0.07 degree, 3-cm nominal ranging accuracy, and vertical elevation accuracy of +/-20 cm for the submerged surface.  Quality checks are built into the data-processing software.
  Completeness_Report: Several regions of the dataset are labeled as "No Data", which corresponds to a cell value of -100 m in the GeoTiff file. These "No Data" areas are a result of the survey not covering a particular region, optical water depth of greater than 1.5 Secchi disc depths, or the manual removal of Lidar processing artifacts.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report: Raw elevation measurements have been determined to be within 1 meter horizontal accuracy. Processing steps (grid interpolation) may introduce additional error which has not been tested at the time of this publication.
      Quantitative_Horizontal_Positional_Accuracy_Assessment:
        Horizontal_Positional_Accuracy_Value: 1
    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report: Elevations of the DEM are vertically consistent with the point elevation data, +/-20 cm.
      Quantitative_Vertical_Positional_Accuracy_Assessment:
        Vertical_Positional_Accuracy_Value: .20
  Lineage:
    Source_Information:
      Type_of_Source_Media: Point elevation measurements collected by the EAARL sensor.
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Single_Date/Time:
            Calendar_Date: 20060417
        Source_Currentness_Reference: ground condition
    Process_Step:
      Process_Description: The data are collected using a NOAA DeHavilland Twin Otter aircraft. The NASA Experimental Advanced Airborne Research Lidar (EAARL) laser scanner collects the data using a green (532nm) raster scanning laser, while a digital camera acquires a visual record of the flight. The data are stored on hard drives and archived at the USGS office in St. Petersburg and the NASA office at Wallops Flight Facility. The navigational data are processed at Wallops Flight Facility.  The navigational and raw data are then downloaded into the Airborne Lidar Processing System (ALPS).  Data are converted from units of time to x,y,z points for elevation. The derived surface data can then be converted into raster data (geotiffs).
      Process_Contact:
        Contact_Information:
          Contact_Organization_Primary:
            Contact_Organization: United States Geological Survey, FISC St. Petersburg
            Contact_Person: Amar Nayegandhi
          Contact_Position: Computer Scientist
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: Florida
            Postal_Code: 33701
            Country: USA
          Contact_Voice_Telephone: 727-803-8747
          Hours_of_Service: 8am to 5pm M-F EST
          Contact_Instructions: Call Survey for Details
    Process_Step:
      Process_Description: The raster dataset was opened in ERDAS IMAGINE for editing. An Area of Interest (AOI) polygon was drawn around regions of poor data quality. Poor data quality was determined visually by locating gaps in the data as well as artifacts of the Lidar processing. Pixels within the AOI polygons were given a raster value of -100 to correspond with other areas of No Data.
      Process_Contact:
        Contact_Information:
          Contact_Organization_Primary:
            Contact_Organization: National Park Service South Florida/Caribbean Network
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 18001 Old Cutler Road, Suite 419
            City: Palmetto Bay
            State_or_Province: FL
            Postal_Code: 33157
            Country: USA
          Contact_Voice_Telephone: (305) 252-0347
          Contact_Facsimile_Telephone: (305) 253-0463
    Process_Step:
      Process_Description: Metadata imported into ArcCatalog from XML file.
      Process_Date: 20070808
      Process_Contact:
        Contact_Information:
          Contact_Organization_Primary:
            Contact_Organization: U. S. Gological Survery, FISC St. Petersburg
          Contact_Address:
            Address_Type: mailing and physical address
            Address: 600 4th Street South
            City: St. Petersburg
            State_or_Province: Florida
            Postal_Code: 33701
            Country: USA
          Contact_Voice_Telephone: 727-803-8747
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Raster
  Raster_Object_Information:
    Raster_Object_Type: Pixel
    Row_Count: 2001
    Column_Count: 2001
    Vertical_Count: 1
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Grid_Coordinate_System:
        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_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: row and column
        Coordinate_Representation:
          Abscissa_Resolution: 1.000000
          Ordinate_Resolution: 1.000000
        Planar_Distance_Units: meters
    Geodetic_Model:
      Horizontal_Datum_Name: North American Datum of 1983
      Ellipsoid_Name: Geodetic Reference System 80
      Semi-major_Axis: 6378137.000000
      Denominator_of_Flattening_Ratio: 298.257222
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: GeoTiff
  Overview_Description:
    Entity_and_Attribute_Overview: This Digital Elevation Model is a GeoTiff derived from point data. It is raster data consisting of cells. Each cell has an elevation value associated with it. Cell size is 1 meter by 1 meter.
    Entity_and_Attribute_Detail_Citation: This Digital Elevation Model is a GeoTIFF derived from point data referenced to WGS84, NAD83 UTM eastings and northings (m). The variables measured by EAARL are: distance between aircraft and GPS satellites (m), attitude information (roll, pitch, heading in degrees), scan angle (degrees), second of the epoch (sec), and 1-ns time-resolved return intensity waveform (digital counts). It is raster data consisting of cells. Each cell has an elevation value associated with it. Cell size is 1 meter by 1 meter.
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U. S. Gological Survery
        Contact_Person: Jerry Butcher
      Contact_Position: Windows System Administrator
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 600 4th Street South
        City: St. Petersburg
        State_or_Province: Florida
        Postal_Code: 33701
        Country: USA
      Contact_Voice_Telephone: 727-803-8747 ext3049
      Contact_Facsimile_Telephone: (727) 803-2031
      Hours_of_Service: 8am to 5pm M-F EST
  Resource_Description: EAARL Submarine Topography-Florida Keys National Marine Sanctuary
  Distribution_Liability: The U. S. Geological Survey shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics are not legal documents and are not intended to be used as such.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: TIFF
        Format_Version_Number: January 2007
        Format_Specification: GeoTiff
        Transfer_Size: 0.000
      Digital_Transfer_Option:
        Offline_Option:
          Offline_Media: DVD
    Fees: 0
    Ordering_Instructions: Call U. S. Gological Survery for Details
  Custom_Order_Process: Call U. S. Gological Survery for Details
  Available_Time_Period:
    Time_Period_Information:
      Multiple_Dates/Times:
        Single_Date/Time:
          Calendar_Date: 20060417
        Single_Date/Time:
          Calendar_Date: 20060418
        Single_Date/Time:
          Calendar_Date: 20060419
        Single_Date/Time:
          Calendar_Date: 20060420
Metadata_Reference_Information:
  Metadata_Date: 20070808
  Metadata_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U. S. Gological Survery, FISC St. Petersburg
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 600 4th Street South
        Address: 
        City: St. Petersburg
        State_or_Province: Florida
        Postal_Code: 33701
        Country: USA
      Contact_Voice_Telephone: 727-803-8747
      Hours_of_Service: 8am to 5pm M-F EST
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Time_Convention: local time
  Metadata_Access_Constraints: None
  Metadata_Use_Constraints: None