Bathymetric Digital Elevation Model (DEM) of the 2016 nearshore coastal bathymetry from West Ship Island to Horn Island, Gulf Islands National Seashore, Mississippi.

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

Frequently anticipated questions:

What does this data set describe?

Title:
Bathymetric Digital Elevation Model (DEM) of the 2016 nearshore coastal bathymetry from West Ship Island to Horn Island, Gulf Islands National Seashore, Mississippi.
Abstract:
The United States Geological Survey Saint Petersburg Coastal and Marine Science Center (USGS SPCMSC), in cooperation with the United States Army Corps of Engineers (USACE) conducted bathymetric surveys of the nearshore waters surrounding Ship and Horn Islands, Gulf Islands National Seashore, Mississippi (GUIS). Camille Cut separates Ship Island into East Ship Island and West Ship Island. The objective of this study was to establish base-level elevation conditions around West Ship Island, East Ship Island, Horn Island and their associated active littoral system prior to restoration activities. These activities include the closure of Camille Cut and the placement of sediment in the littoral zone of West Ship Island. This survey will be used to verify sediment migration patterns by monitoring elevation change over time. The dataset produced by this survey will also be compared with historic bathymetric datasets to help further understand island elevation over time. This data release provides 667-line kilometers (km) of processed Single-Beam Bathymetry (SBB) data and 773-line km of processed Interferometric Bathymetry (IFB) collected by the USGS SPCMSC in July 2016 (field activity number [FAN] 2016-347-FA). The IFB data were acquired aboard the Research Vessel (RV) Sallenger (subFAN, 16BIM04), and the SBB data were acquired aboard the RV Jabba Jaw (subFAN, 16BIM05) and the RV Mako (subFAN, 16BIM06). The IFB and SBB point data are provided in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00), ellipsoid height (-49.70 meters [m] to -28.87 m); 2) the North American Datum of 1983 (NAD83) CORS96 realization and the North American Vertical Datum 1988 (NAVD88) with respect to the GEOID12B model (-0.07 m to -20.69 m); and 3) NAD83 (CORS96) and Mean Lower Low Water (MLLW) (-0.04 m to -20.60 m). This metadata record describes the comprehensive, 50-meter (m) Digital Elevation Model (DEM) created from the IFB and SBB point data and provided in NAD83 NAVD88 GEOID12B. For additional information regarding data collection and processing, please refer to the field logs and formal Federal Geographic Data Committee (FGDC) metadata for the individual XYZ point data files and survey trackline shapefiles also included within this data release (https://doi.org/10.5066/F7B8571Q).
Supplemental_Information:
The single-beam surveys were acquired and processed to a geodetic reference ellipsoid. The single-beam data were collected using stand-alone GPS and then post-processed to obtain Differential Global Positioning System (DGPS) navigation. All single-beam surveys were referenced to the World Geodetic System of 1984 (WGS84 [G1150]), which is equivalent to ITRF00. The final x,y,z position data from each survey were merged to generate a one single-beam x,y,z point file for merging with the IFB data also collected during this survey.
  1. How might this data set be cited?
    DeWitt, Nancy T., Stalk, Chelsea A., Fredericks, Jake J., Flocks, James G., Kelso, Kyle W., Farmer, Andrew S., Tuten, Thomas M., and Buster, Noreen A., 20170930, Bathymetric Digital Elevation Model (DEM) of the 2016 nearshore coastal bathymetry from West Ship Island to Horn Island, Gulf Islands National Seashore, Mississippi.: U.S. Geological Survey Data Release doi:10.5066/F7B8571Q, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.999591
    East_Bounding_Coordinate: -88.500454
    North_Bounding_Coordinate: 30.268648
    South_Bounding_Coordinate: 30.190648
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 13-Jul-2016
    Ending_Date: 19-Jul-2016
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: tabular digital data
  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.
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 16
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -87.000000
      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 0.1
      Ordinates (y-coordinates) are specified to the nearest 0.1
      Planar coordinates are specified in meter
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: International Reference Frame 2000 (ITRF00)
      Depth_Resolution: 0.01
      Depth_Distance_Units: meter
      Depth_Encoding_Method: Implicit coordinate
  7. How does the data set describe geographic features?
    Ship_Horn_Island_2016_SBB_ITRF00_xyz.txt
    ASCII text file containing the processed single-beam bathymetry x,y,z point data in the International Terrestrial Reference Frame of 2000 (ITRF00). (Source: USGS)
    ITRF00_X
    ITRF00 X-coordinate (easting) of sample point, in meters (Source: CARIS)
    Range of values
    Minimum:307633.312
    Maximum:355563.528
    ITRF00_Y
    ITRF00 Y-coordinate (northing) of sample point, in meters (Source: CARIS)
    Range of values
    Minimum:3341598.284
    Maximum:3349508.415
    Ellipsoid
    ITRF00 ellipsoid height of sample point, in meters (Source: CARIS)
    Range of values
    Minimum:-49.696
    Maximum:-28.867
    Year
    The year the data were collected (Source: USGS) 2016
    DataType
    Type of bathymetric data (Source: USGS) SBB
    Ship_Horn_Island_2016_SBB_NAD83_NAVD88_GEOID12B_xyz.txt
    ASCII text file containing the processed single-beam bathymetry x,y,z point data in the North American Datum 1983 (NAD83) and the North American Vertical Datum 1988 (NAVD88) with respect to the GEOID12B model. (Source: VDatum version 3.6)
    NAD83_X
    NAD83 X-coordinate (Easting) of sample point, in meters (Source: VDatum version 3.6)
    Range of values
    Minimum:307634.0906
    Maximum:355564.296
    NAD83_Y
    NAD83 Y-coordinate (Northing) of sample point, in meters (Source: VDatum version 3.6)
    Range of values
    Minimum:3341597.6941
    Maximum:3349507.8221
    NAVD88_G12B
    the Z-coordinate in North American Vertical Datum 1988, GEOID12B (orthometric height) of sample point, in meters (Source: VDatum version 3.6)
    Range of values
    Minimum:-20.6856
    Maximum:-0.0731
    Year
    The year the data were collected (Source: USGS) 2016
    DataType
    The data type of the xyz point - SBB (Single-Beam Bathymetry) (Source: USGS) SBB
    NAD83_Long
    NAD83 Longitude-coordinate of sample point, in decimal degrees. (Source: VDatum version 3.6)
    Range of values
    Minimum:-88.998285
    Maximum:-88.500898
    NAD83_Lat
    NAD83 Latitude-coordinate of sample point, in decimal degrees (Source: VDatum version 3.6)
    Range of values
    Minimum:30.191274
    Maximum:30.2626594
    Ship_Horn_Island_2016_SBB_NAD83_MLLW_5m_xyz.txt
    ASCII text file containing the processed single-beam bathymetry x,y,z point data in NAD83 and Mean Lower Low Water (MLLW). (Source: VDatum version 3.6)
    NAD83_X
    NAD83 X-coordinate (easting) of sample point, in meters (Source: VDatum version 3.6)
    Range of values
    Minimum:307634.0906
    Maximum:355564.296
    NAD83_Y
    NAD83 Y-coordinate (northing) of sample point, in meters (Source: VDatum version 3.6)
    Range of values
    Minimum:3341597.6941
    Maximum:3349507.8221
    MLLW
    The Z-coordinate in Mean Lower Low Water (MLLW) of sample point, in meters (Source: VDatum version 3.6)
    Range of values
    Minimum:-20.60
    Maximum:-0.040
    Year
    The year the data were collected (Source: USGS) 2016
    DataType
    The data type of the xyz point - SBB (Single-Beam Bathymetry) (Source: USGS) SBB
    NAD83_Long
    NAD83 Longitude-coordinate of sample point, in decimal degrees. (Source: VDatum version 3.6)
    Range of values
    Minimum:-88.998285
    Maximum:-88.500898
    NAD83_Lat
    NAD83 Latitude-coordinate of sample point, in decimal degrees (Source: VDatum version 3.6)
    Range of values
    Minimum:30.191274
    Maximum:30.2626594
    Ship_Horn_Island_2016_SBB_ITRF00_tracklines.shp and Ship_Horn_Island_2016_SBB_NAD83_tracklines.shp
    Esri shapefile containing the survey tracklines for the single-beam bathymetry data collected in July 2016 nearshore Ship Island and Horn Island, Mississippi during USGS FAN 2015-347-FA which includes subfans 16BIM05 and 16BIM06. File Ship_Horn_Island_2016_SBB_ITRF00_tracklines.shp is projected in WGS84, UTM Zone 16N. File Ship_Horn_Island_2016_SBB_NAD83_tracklines.shp is projected in NAD83, UTM Zone 16N. A vertical component does not exist for these files. (Source: Esri)
    FID
    Internal feature number. (Source: Esri) Sequential unique whole numbers that are automatically generated.
    Shape
    Feature geometry. (Source: Esri) Polyline ZM is the geometry type defining the features.
    HYPACKLine
    Trackline name assigned by HYPACK-A Xylem Brand acquisition software version 15.09.71 for 16BIM05 and 16BIM06 with the USGS subFAN number appended to the beginning of the file. For example, in 16BIM05_001_1451, 16BIM05 denotes the USGS subFAN number, 001 denotes the line number, and 1451 denotes the time HYPACK started recording the line. Some line names deviate from this scheme having a truncated time stamp or an additional extension such as *_0001, *_0002,*_0003, *_#P00, or *_##P00. This resulted from program performance issues in HYPACK during the survey. (Source: HYPACK)
    Range of values
    Minimum:16BIM05_001_1451
    Maximum:16BIM06_184
    Year
    The year the data were collected (Source: USGS) 2016
    Lenth_m
    Length of survey line, in meters (Source: Esri)
    Range of values
    Minimum:0.58
    Maximum:10091.34
    Units:meters
    Resolution:0.01

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Nancy T. DeWitt
    • Chelsea A. Stalk
    • Jake J. Fredericks
    • James G. Flocks
    • Kyle W. Kelso
    • Andrew S. Farmer
    • Thomas M. Tuten
    • Noreen A. Buster
  2. Who also contributed to the data set?
    U.S. Geological Survey, Coastal and Marine Geology Program, St. Petersburg Coastal and Marine Science Center
  3. To whom should users address questions about the data?
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov

Why was the data set created?

This zip archive contains trackline shapefiles or processed SBB x,y,z point data for the SBB collected in July 2016 (FAN 2016-347-FA; subFANs 16BIM05 and 16BIM06) nearshore from West Ship Island to Horn Island, GUIS, Mississippi. The processed single-beam soundings are provided in comma delimited American Standard Code for Information Interchange (ASCII) format.

How was the data set created?

  1. From what previous works were the data drawn?
  2. How were the data generated, processed, and modified?
    Date: 2016 (process 1 of 8)
    GPS Acquisition: Three benchmark locations were occupied, two on Horn Island and one on Ship Island. On Horn Island, the first benchmark, 202Q 1998 (USACE) was located at the ranger station's trail head south of the pier. The second benchmark WHRN (USGS SPCMSC) was located on the western end of Horn Island atop short sand ridge, on the sound side of the island. The Ship Island benchmark PID BBCL83, stamping 4756 F 2011 (John Oswald and Associates, LLC) was located on the north side of the intersection where the main boardwalk meets the generator shed boardwalk. Each base was equipped with an Ashtech ProFlex GPS receiver, which recorded the 12-channel full-carrier-phase positioning signals (L1/L2) from satellites via the Thales choke-ring antenna at a rate of 2 times per second. GPS instrumentation was duplicated on all single-beam survey vessels (rovers), which recorded concurrently at 2 times per second. The GPS navigation data were acquired and processed in WGS84 (G1150). Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Date: 2016 (process 2 of 8)
    Single-Beam Bathymetry Acquisition: Depth soundings were acquired aboard all vessels at 100-milliseconds (ms) using an Odom CV100 echo sounder system with a 200 kilohertz (kHz) transducer. Boat motion was recorded on the R/V Jabba Jaw (16BIM05) using an SBG Ellipse A motion sensor, and the R/V Mako (16BIM06) using a TSS Dynamic Motion Sensor (TSS DMS-05). All sensor data were combined and saved into a single raw data file (.raw) in HYPACK version 15.0.9.71, with each device string referenced by a device identification code and time stamped to Coordinated Universal Time (UTC). Sound velocity measurements were collected using Sontek Castaway CTD units to record changes in water column speed of sound (SOS). Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Data sources produced in this process:
    • HYPACK raw data files (.raw), HYPACK target files (.tgt), and SVP files (.txt, *.csv, *.svp).
    Date: 2016 (process 3 of 8)
    Differentially corrected navigation processing: The coordinate values for each of the GPS base stations (202Q, and WHRN) are the time-weighted average of values obtained from the National Geodetic Survey's (NGS) On-Line Positioning User Service (OPUS). Because there was only one session for benchmark 4756 F 2011, the published coordinates were used. The coordinates were imported into the post-processing software GrafNav (Waypoint Product Group) version 8.6. For post-processing, the kinematic GPS data from the survey vessels were processed to the concurrent GPS data from the closest base stations. Steps were taken to ensure that the trajectories between the base and rover were clean and resulted in fixed positions. GPS data quality could be monitored and manipulated by analyzing the graphs, trajectory maps, and processing logs that GrafNav produces for each GPS session. If poor GPS data were identified, some common tools used to improve the solution were utilized. These options included, but were not limited to, omitting a satellite flagged as poor in health, excluding time-segments with cycle slips, or adjusting the satellite elevation mask angle. The final, differentially-corrected, precise DGPS positions were computed at each roving vessels respective recording rate, and then exported in ASCII text format. The exported ASCII file then replaced the uncorrected real-time rover positions recorded during acquisition later in processing. The GPS data were processed and exported in the WGS84 (G1150) geodetic datum. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Data sources produced in this process:
    • Post-processed differential navigation data for the rover (boat) in ASCII text format.
    Date: 2016 (process 4 of 8)
    Single-beam bathymetry processing: All data were processed using CARIS HIPS and SIPS (Hydrographic Information Processing System and Sonar Information Processing System) version 9.1. The raw HYPACK data files were imported into CARIS where the differentially corrected navigation files were imported using the generic data parser tool within CARIS, and any SVP profile casts were applied. The bathymetric data components (position, motion, depth, and SOS) were then merged and geometrically corrected to produce processed x,y,z data. Next, the data were edited for outliers and then further reviewed in the Subset Editor utility for crossing status, and questionable data points or areas. The geometrically corrected point data were then exported as an x,y,z ASCII text file referenced to WGS84 (G1150), equivalent to ITRF00, and ellipsoid height in meters. The exported ASCII files from each vessel were then combined into one file for further quality assurance and quality control. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • Post-processed differential navigation data files (*.txt), HYPACK RAW bathymetric data files (*.RAW), HYPACK target (.tgt) files, and SVP files (.txt, *.csv, *.svp) files all in ASCII text format.
    Data sources produced in this process:
    • 16BIM05_SBB_Level_03_ITRF00.txt 16BIM06_SBB_Level_03_ITRF00.txt
    Date: 2016 (process 5 of 8)
    Single-beam bathymetry error analysis: The ASCII files described in the previous step were imported into ArcMap version 10.3 and reviewed for outliers. An Esri ArcMap add-in program script was written locally, by USGS staff to evaluate the elevation differences at the intersection of crossing lines. If discrepancies were found at a crossing, the source of the discrepancies was identified and, if needed, the line or segment of data points in error was statically adjusted or removed. This process was reiterated again to produce a final assessment of the crossing range for the SBB dataset. Person who carried out this activity:
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • 16BIM05_SBB_Level_03_ITRF00.txt 16BIM06_SBB_Level_03_ITRF00.txt
    Data sources produced in this process:
    • 16BIM05_SBB_Level_03_ITRF00_lines_removed_draft1a.txt 16BIM06_SBB_Level_03_ITRF00.txt Ship_Horn_2016_SBB_ITRF00_xyz.txt
    Date: 2016 (process 6 of 8)
    VDatum version 3.6 transformation: The SBB data were transformed two times, using VDatum. The vertical transformation errors reported by VDatum are the following: 1) Transformation from ITRF00 to NAD83, NAVD88 with respect to GEOID12B is 0.0762 m or 7.62 cm for the vertical area named GEOID12B; and 2) Transformation from NAD83, NAVD88 with respect to GEOID12B to NAD83, MLLW is 0.163 m or 16.30 cm for the vertical area named LAmobile02-8301. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Nancy T. DeWitt
    Geologist
    600 4th Street South
    St. Petersburg, FL
    U.S.

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • 16BIM05_SBB_Level_03_ITRF00_lines_removed_draft1a.txt 16BIM06_SBB_Level_03_ITRF00.txt
    Data sources produced in this process:
    • Ship_Horn_Island_2016_SBB_NAD83_NAVD88_GEOID12B_xyz.txt Ship_Horn_Island_2016_SBB_NAD83_MLLW_xyz.txt
    Date: 2016 (process 7 of 8)
    The trackline files were created separately for 16BIM05 and 16BIM06 from the x,y,z point files in Esri ArcGIS version 10.3 using the XTools Pro extension, version 11.1. Using the "XTools" feature conversion tool, "make polylines from points" the x,y,z data point shapefile was converted into a polyline shapefile. This was repeated for each vessel. Both resultant polyline shapefiles were then merged into one file for the data release and projected in NAD83 Universal Transverse Mercator (UTM) Zone 16 North. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Nancy T. DeWitt
    Geologist
    St. Petersburg, FL

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
    Data sources used in this process:
    • 16BIM05_SBB_Level_003_xxx_ITRF00_tracklines_lines_removed_forDraft1a.shp 16BIM06_SBB_Level_003_xxx_ITRF00_tracklines.shp
    Data sources produced in this process:
    • Ship_Horn_Island_2016_SBB_ITRF00_tracklines.shp Ship_Horn_Island_2016_SBB_NAD83_tracklines.shp
    Date: 13-Oct-2020 (process 8 of 8)
    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?

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

  1. How well have the observations been checked?
    The accuracy of the data is determined during data collection. The SBB data were collected during one research effort in July, 2016, USGS FAN 2015-347-FA, subFANs 16BIM05 and 16BIM06. This dataset utilized two vessels and is therefore internally consistent per platform. Methods were employed to maintain data collection consistency aboard each platform. During mobilization, each piece of equipment is isolated to obtain internal and external offset measurements with respect to the survey platform. Each system has a dedicated computer, and efforts are made to utilize the same equipment and software versions on all systems. However, upgrades and changes occur and require additional setup, measurements, and notation. DGPS was always implemented for navigational accuracy in post-processing. These bathymetric data have not been independently verified for accuracy.
    For the SBB, offsets between the single-beam transducers, the Ashtech antenna reference point (ARP), and the vessel motion units were measured and accounted for on all platforms. All pertinent measurements were accounted for in the DGPS post-processing software packages (National Geodetic Survey On-Line Positioning User Service (OPUS), and Waypoint Product Group GrafNav, version 8.6).
  2. How accurate are the geographic locations?
    Three benchmark locations were occupied, two on Horn Island and one on Ship Island. On Horn Island, the first benchmark, 202Q 1998 (USACE) was located at the ranger station's trail head south of the pier. The second benchmark WHRN (USGS SPCMSC) was located on the western end of Horn Island atop short sand ridge, on the sound side of the island. The Ship Island benchmark PID BBCL83, stamping 4756 F 2011 (John Oswald and Associates, LLC) was located on the north side of the intersection where the main boardwalk meets the generator shed boardwalk. All the static GPS base station sessions were using the On-Line Positioning User Service (OPUS) maintained by the National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS). The base location results from OPUS were entered into a spreadsheet to compute one final coordinate and error analysis for that base location. Using the OPUS values for each day, and the total time per GPS session, the average weighted value of occupation time was calculated so the longer occupations hold more value than shorter occupations. The final value for latitude, longitude, and ellipsoid height was the weighted average of each GPS session processed with OPUS. This value was entered into GrafNav version 8.6 as the base station coordinates. The range from the average values was calculated, using outputs from OPUS, for each session as the absolute value of the final value minus the daily value. The maximum horizontal range of the base station coordinates used for post-processing the single-beam bathymetry was 0.00026 decimal seconds latitude and 0.00049 decimal seconds longitude for 202Q, 0.00038 decimal seconds latitude and 0.00033 decimal seconds longitude for WHRN. The reported error for 4756 F 2011 is 0.013 meters latitude and 0.012 meters longitude.
  3. How accurate are the heights or depths?
    All static base station sessions for 202Q and WHRN were processed through On-Line Positioning User Service (OPUS) maintained by the National Oceanic and Atmospheric Administration (NOAA) and the National Geodetic Survey (NGS). The base location results from OPUS were entered into a spreadsheet to compute a final, time-weighted positional coordinate (latitude, longitude, and ellipsoid height). Base-station position error for each GPS session was calculated as the absolute value of the final position minus the session position value. SPCMSC standards define the maximum acceptable vertical error for any individual base station GPS session as less than or equal to three times the standard deviation of the ellipsoid height; any occupations exceeding this error are removed, and the base station coordinates are then recalculated and considered final. For 202Q base location, the standard deviation of the ellipsoid height was 0.010 m and the maximum difference from the average ellipsoid for any GPS session was +/- 0.023 m. For WHRN base location, the standard deviation of the ellipsoid height was 0.002 m and the maximum difference from the average ellipsoid for any GPS session was +/- 0.022 m. For the 4756 F 2011 base station only one OPUS session was run so the published coordinates were used. The survey datasheet reports the vertical error of the ellipsoid height as +/- 0.017 m.
  4. Where are the gaps in the data? What is missing?
    These are complete post-processed x,y,z bathymetric data points from acoustic single-beam data collected in July 2016 from the nearshore areas of Ship Island to Horn Island, Mississippi.
  5. How consistent are the relationships among the observations, including topology?
    This file consists of the post-processed bathymetric data (x,y,z) (subFANs 16BIM05, 16BIM06) and represents data coverage for the single-beam portion of the the 2016 nearshore survey (USGS FAN 2015-347-FA) from Ship Island to Horn Island, GUIS, Mississippi. Refer to the supplemental information section of the data release for field logs, vessel platform descriptions, and other survey information.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?
Access_Constraints:
The U.S. Geological Survey requests that it be referenced as the originator of this dataset in any future products or research derived from these data.
Use_Constraints: These data should not be used for navigational purposes.
  1. Who distributes the data set? (Distributor 1 of 1)
    Nancy T. DeWitt
    U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
    Geologist
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8000 (voice)
    ndewitt@usgs.gov
  2. What's the catalog number I need to order this data set? Ship_Horn_Island_2016_SBB_ITRF00_xyz.txt, Ship_Horn_Island_2016_SBB_NAD83_NAVD88_GEOID12B_xyz.txt, Ship_Horn_Island_2016_SBB_NAD83_MLLW_xyz.txt, Ship_Horn_Island_2016_SBB_ITRF00_tracklines.shp, Ship_Horn_Island_2016_SBB_NAD83_tracklines.shp
  3. What legal disclaimers am I supposed to read?
    This publication was prepared by an agency of the United States Government. Although these data were processed successfully on a computer system at the U.S. Geological Survey, no warranty expressed or implied is made regarding the display or utility of the data on any other system, nor shall the act of distribution imply any such warranty. The U.S. Geological Survey shall not be held liable for improper or incorrect use of the data described and (or) contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    The ASCII text files contained in the .zip archives can be accessed with any standard text file reader.

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2020
Metadata author:
Nancy T. DeWitt
U.S. Geological Survey St. Petersburg Coastal and Marine Science Center
Geologist
600 4th Street South
St. Petersburg, FL
USA

(727) 502-8000 (voice)
ndewitt@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/spcmsc/Ship_Horn_Island_2016_SBB_xyz_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:18:52 2021