Multibeam Bathymetry Data Collected in 2016 from Grand Bay Alabama/Mississippi: Unadjusted processed elevation point data (x,y,z)

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Frequently anticipated questions:


What does this data set describe?

Title:
Multibeam Bathymetry Data Collected in 2016 from Grand Bay Alabama/Mississippi: Unadjusted processed elevation point data (x,y,z)
Abstract:
A reconnaissance multibeam bathymetry survey was conducted by the U.S Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center (SPCMSC) in Grand Bay Alabama/Mississippi (AL/MS) on May 12, 2016 as an assessment of the shallow water capabilities of the Teledyne Reson SeaBat T50-P multibeam echosounder, and as an attempt to map the eroding marsh edges at locations of interest around the bay. This dataset, Grand_Bay_2016_MBB_Unadjusted_xyz.zip, includes the resulting [unadjusted] processed elevation point data (x,y,z), as derived from a half meter resolution surface. For this dataset, a static offset was not applied to vertically adjusted the data to match USGS bathymetry data previously acquired in 2015 (DeWitt and others, 2016).
Supplemental_Information:
The processed sonar data are provided as American Standard Code for Information Interchange (ASCII) x,y,z point data files. These values are not the individual soundings but are the exported BASE (Bathymetry with Associated Statistical Error) surface at 0.5-meter (m) spatial distances with associated CUBE (Combined Uncertainty and Bathymetry Estimator) sample surface created from the edited soundings dataset using CARIS HIPS and SIPS version 10.2. These are considered interpolated samples in which one value represents all soundings within a 0.50-meter node, weighted by uncertainty and proximity, giving the final value as a data sample within the specific grid cell. The data were collected and processed in the World Geodetic System of 1984 (WGS84) reference frame. This dataset was subsequently transformed using National Oceanic and Atmospheric Administration (NOAA) VDatum version 3.7 transformation software (http://vdatum.noaa.gov/). The data were transformed from WGS84 (G1674) horizontally to the North American Datum of 1983 (NAD83 [2011]) and then vertically to the North American Vertical Datum of 1988 (NAVD88) relative to the GEOID model of 2012 version A (GEOID12A).
  1. How might this data set be cited?
    Stalk, Chelsea A., Fredericks, Jake J., Locker, Stanley D., and Carlson, Cody S., 20200716, Multibeam Bathymetry Data Collected in 2016 from Grand Bay Alabama/Mississippi: Unadjusted processed elevation point data (x,y,z): U.S. Geological Survey Data Release doi:10.5066/F7MC8Z9N, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -88.411770
    East_Bounding_Coordinate: -88.395593
    North_Bounding_Coordinate: 30.384007
    South_Bounding_Coordinate: 30.364026
  3. What does it look like?
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 12-May-2016
    Ending_Date: 12-May-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_and_Vector_Object_Count 288248 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: 0.999600
      Longitude_of_Central_Meridian: -87.0
      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 World Geodetic System of 1984.
      The ellipsoid used is WGS_84.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257223563.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: World Geodetic System of 1984
      Altitude_Resolution: 0.001
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: Attribute values
  7. How does the data set describe geographic features?
    Grand_Bay_2016_MBB_WGS84_0.5m_Unadjusted_xyz.txt
    Comma separated text (.txt) file containing the processed 0.5-m resolution multibeam bathymetry x,y,z samples in the WGS84 G1674 realization (ellipsoid height). This file has not been vertically adjusted to match previously collected local bathymetry data provided in DeWitt and others (2016). (Source: HYPACK)
    WGS84_X
    WGS84 Universal Transverse Mercator (UTM) zone 16N X-coordinate (easting) of sample point, in meters. (Source: HYPACK)
    Range of values
    Minimum:364358.312
    Maximum:365886.001
    Resolution:0.001
    WGS84_Y
    WGS84 UTM zone 16N Y-coordinate (northing) of sample point, in meters. (Source: HYPACK)
    Range of values
    Minimum:3359968.214
    Maximum:3362164.130
    Resolution:0.001
    Ellipsoid
    WGS84 (ellipsoid height) of sample point, in meters. (Source: HYPACK)
    Range of values
    Minimum:-30.600
    Maximum:-27.980
    Resolution:0.001
    DataType
    MBB = Multibeam Bathymetry; USGS SPCMSC identifier of bathymetry data type. (Source: USGS) Character string - MBB
    Year
    Year data were collected (Source: USGS) 2016
    HypackLine
    Line name assigned by HYPACK during acquisition. (Source: HYPACK) Line number followed by segment number and Coordinated Universal Time (UTC) at start of line.
    Site
    Site identifier for data. (Source: USGS) SITE_1, SITE_2, SITE_3
    Grand_Bay_2016_MBB_NAD83_0.5m_Unadjusted_xyz.txt
    Comma separated values text (.txt) file containing the processed 0.5-m resolution multibeam bathymetry x,y,z samples in NAD83 (2011). This file has not been vertically adjusted to match previously collected local bathymetry data provided in DeWitt and others (2016). (Source: HYPACK; VDatum)
    NAD83_X
    NAD83 UTM zone 16N X-coordinate (easting) of sample point, in meters. (Source: HYPACK; VDatum)
    Range of values
    Minimum:364359.093
    Maximum:365886.781
    Resolution:0.001
    NAD83_Y
    NAD83 UTM zone 16N Y-coordinate (northing) of sample point, in meters. (Source: HYPACK; VDatum)
    Range of values
    Minimum:3359967.619
    Maximum:3362163.534
    Resolution:0.001
    NAD83_Ellipsoid
    NAD83 (ellipsoid height) of sample point, in meters. (Source: HYPACK; VDatum)
    Range of values
    Minimum:-29.200
    Maximum:-26.580
    Resolution:0.001
    DataType
    MBB = Multibeam Bathymetry; USGS SPCMSC identifier of bathymetry data type. (Source: USGS) Character string - MBB
    Year
    Year data were collected (Source: USGS) 2016
    HypackLine
    Line name assigned by HYPACK during acquisition. (Source: HYPACK) Line number followed by segment number and UTC time at start of line.
    Site
    Site identifier for data. (Source: USGS) SITE_1, SITE_2, SITE_3
    Grand_Bay_2016_MBB_NAD83_NAVD88_GEIOID12A_0.5m_Unadjusted_xyz.txt
    Comma separated values text (.txt) file containing the processed 0.5-m resolution multibeam bathymetry x,y,z samples in NAD83 (2011), NAVD88 using the GEOID12A model (orthometric height). This file has not been vertically adjusted to match previously collected local bathymetry data provided in DeWitt and others (2016). (Source: HYPACK; VDatum)
    NAD83_X
    NAD83 UTM zone 16N X-coordinate (easting) of sample point, in meters (Source: HYPACK; VDatum)
    Range of values
    Minimum:364359.093
    Maximum:365886.781
    Resolution:0.001
    NAD83_Y
    NAD83 UTM zone 16N Y-coordinate (northing) of sample point, in meters (Source: HYPACK; VDatum)
    Range of values
    Minimum:3359967.619
    Maximum:3362163.534
    Resolution:0.001
    NAVD88_GEOID12A
    NAVD88 (orthometric height) of sample point, in meters with respect to GEOID12A. (Source: HYPACK; VDatum)
    Range of values
    Minimum:-1.110
    Maximum:1.503
    Resolution:0.001
    DataType
    MBB = Multibeam Bathymetry; USGS SPCMSC identifier of bathymetry data type. (Source: USGS) Character string - MBB
    Year
    Year data were collected (Source: USGS) 2016
    HypackLine
    Line name assigned by HYPACK during acquisition. (Source: HYPACK) Line number followed by segment number and UTC time at start of line.
    Site
    Site identifier for data. (Source: USGS) SITE_1, SITE_2, SITE_3

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Chelsea A. Stalk
    • Jake J. Fredericks
    • Stanley D. Locker
    • Cody S. Carlson
  2. Who also contributed to the data set?
    U.S. Geological Survey, Sea-level and Storm Impacts on Estuarine Environments and Shorelines (SSIEES) program, St. Petersburg Coastal and Marine Science Center.
  3. To whom should users address questions about the data?
    Chelsea A. Stalk
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    600 4th Street South
    St. Petersburg, FL
    USA

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

Why was the data set created?

The purpose of the survey was to assess the capabilities of the Teledyne Reson SeaBat T50-P multibeam echosounder and attempt to image eroding marsh edges at areas of interest within Grand AL/MS. In order to extend the horizontal coverage and esonify the shallow water marsh edges, the head of the system was tilted at an angle of 30 degrees to the port side of the vessel. Data were collected during USGS field activity number (FAN) 2016-331-FA aboard the R/V Jabba Jaw, a 22-foot (ft) fiberglass shallow draft center console catamaran. Additional survey and data details are available from the USGS Coastal and Marine Geoscience Data System (CMGDS) at, https://cmgds.marine.usgs.gov/fan_info.php?fan=2016-331-FA.

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: 12-May-2016 (process 1 of 4)
    Acquisition: Multibeam data were acquired using a Teledyne Reson SeaBat T50-P multibeam echosounder mounted to the bow of the R/V Jabba Jaw, a 22-ft fiberglass shallow draft center console catamaran. An Applanix Pos MV Wavemaster II V5 Inertial Measurement Unit was mounted on top of the sonar bracket in the water and was used for positioning and attitude. Two Trimble 540AP GPS antennas were affixed to the top of the sonar mount pole. A functioning sound velocity sensor was not available for speed of sound readings at the head. A Sontek Castaway CTD was used for sound velocity profiles and speed of sound values. Hydrographic survey acquisition and processing software, HYPACK/HYSWEEP (version 2015) managed data inputs from sensors and produced two files (.RAW and .HSX). Data were collected in WGS84 (G1674). Person who carried out this activity:
    Cody S. Carlson
    Seafloor Systems Inc.
    4415 Commodity Way
    SShingle Springs, CA
    USA

    503-677-1019 (voice)
    cody@seafloorsystems.com
    Date: 25-Apr-2017 (process 2 of 4)
    Processing: Positioning and attitude data were post-processed in Applanix POSPac MMS software version 8.0. Raw position files were imported into POSPac and processed with the single-base function utilizing Continuously Operating Reference Station (CORS) ALDI (https://www.ngs.noaa.gov/CORS/Sites/aldi.html). ALDI coordinates were verified using National Geodetic Survey (NGS) data sheets, the data were then processed using the Global Navigation Satellite System Inertial Processor function. Upon post-processing, a smoothed best estimate of trajectory (SBET) file was created and exported in WGS84 (G1674). Bathymetric data were post-processed using two separate hydrographic processing software systems. First, .HSX files were imported into HYPACK MBMAX64, version 2015, where sounding (x,y,z) position and motion data were corrected using the SBET file described above. Data were then cleaned using filters and manual editing. A sounding artifact near nadir was identified and manually removed. Data were then exported as a .HS2X file and imported into CARIS Hydrographic processing software version 10.2. Collected sound velocity profiles were applied to account for changes in the speed of sound within the water column during the survey. Refraction artifacts were present in the data and were resolved using the Refraction Editor. A roll calibration was performed, and data were examined and further cleaned using Subset Editor. A 0.50-m bathymetric CUBE surface was computed and the final surface was exported as an x,y,z ASCII file using the Base Surface to ASCII function. Person who carried out this activity:
    Chelsea A. Stalk
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    600 4th Street South
    St. Petersburg, FL
    USA

    (727)502-8000 (voice)
    cstalk@usgs.gov
    Data sources produced in this process:
    • Grand_Bay_2016_MBB_WGS84_0.5m_Unadjusted_xyz.txt
    Date: 22-Dec-2017 (process 3 of 4)
    Datum Transformation: Final x,y,z data were converted using version 3.7 of NOAA’s VDatum software conversion tool (reported vertical transformation error is 5.4 centimeters) from the WGS84 G1674 realization to NAD83 (2011) with ellipsoid heights. In addition, the data were transformed horizontally from WGS84 to NAD83 and vertically to NAVD88, using the GEOID12A model (orthometric height). Person who carried out this activity:
    Chelsea A. Stalk
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    600 4th Street South
    St. Petersburg, FL
    USA

    (727)502-8000 (voice)
    cstalk@usgs.gov
    Data sources produced in this process:
    • Grand_Bay_2016_MBB_NAD83_0.5m_Unadjusted_xyz.txt, Grand_Bay_2016_MBB_NAD83_NAVD88_GEOID12A_0.5m_Unadjusted_xyz.txt
    Date: 13-Oct-2020 (process 4 of 4)
    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?
    DeWitt, Nancy T., Stalk, Chelsea A., Smith, Christopher G., Locker, Stanley D., Fredericks, Jake J., McCloskey, Terrance A., and Wheaton, Cathryn J., 20161122, Single-Beam Bathymetry Data Collected in 2015 from Grand Bay, Mississippi/Alabama: U.S. Geological Survey Data Release doi:10.5066/F7NP22M2, U.S. Geological Survey, St. Petersburg, FL.

    Online Links:


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

  1. How well have the observations been checked?
    This dataset was from one research cruise and was therefore internally consistent. Methods were employed to maintain data collection consistency aboard the platform. During mobilization, each piece of equipment was isolated to obtain internal and external offset measurements with respect to the survey platform. All the critical measurements were recorded manually and digitally entered into their respective programs. The data have not been independently verified for accuracy.
  2. How accurate are the geographic locations?
    An Applanix POS MV Wavemaster II system was used to provide position and attitude data during data collection and accounted for vessel motion such as heave, pitch, and roll. Post-processed navigation data have a reported horizontal accuracy of 0.045 meters.
  3. How accurate are the heights or depths?
    Vertical accuracy of the post-processed navigation data is reported as 0.018 m.
  4. Where are the gaps in the data? What is missing?
    These are complete post-processed unadjusted x,y,z bathymetric data points from acoustic multibeam data collected in Grand Bay Alabama/Mississippi, May 2016.
  5. How consistent are the relationships among the observations, including topology?
    This file represents the post-processed unadjusted bathymetric data (x,y,z) collected during a multibeam bathymetry survey.

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)
    Chelsea A. Stalk
    U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
    600 4th Street South
    St. Petersburg, FL
    USA

    (727) 502-8114 (voice)
    cstalk@usgs.gov
  2. What's the catalog number I need to order this data set? Grand_Bay_2016_MBB_WGS84_0.5m_Unadjusted_xyz.txt, Grand_Bay_2016_MBB_NAD83_0.5m_Unadjusted_xyz.txt, Grand_Bay_2016_MBB_NAD83_NAVD88_GEOID12A_0.5m_Unadjusted_xyz.txt
  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:
Chelsea A. Stalk
U.S. Geological Survey - St. Petersburg Coastal and Marine Science Center
Electronics Technician (Marine Instrumentation)
600 4th Street South
St. Petersburg, FL
USA

(727) 502-8000 (voice)
cstalk@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

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