Multibeam bathymetric data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA using a Teledyne SeaBat Integrated Dual-Head (IDH) T20-P multibeam echosounder (32-bit GeoTIFF, UTM Zone 19N, NAD 83, MLLW Datum, 2-m resolution)

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

Frequently anticipated questions:

What does this data set describe?

Title:
Multibeam bathymetric data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA using a Teledyne SeaBat Integrated Dual-Head (IDH) T20-P multibeam echosounder (32-bit GeoTIFF, UTM Zone 19N, NAD 83, MLLW Datum, 2-m resolution)
Abstract:
In June 2022, the U.S. Geological Survey, in collaboration with the Massachusetts Office of Coastal Zone Management, collected high-resolution geophysical data, in Nantucket Sound to understand the regional geology in the vicinity of Horseshoe Shoal. This effort is part of a long-term collaboration between the USGS and the Commonwealth of Massachusetts to map the State’s waters, support research on the Quaternary evolution of coastal Massachusetts, resolve the influence of sea-level change and sediment supply on coastal evolution, and strengthen efforts to understand the type, distribution, and quality of subtidal marine habitats. This collaboration produces high-resolution geologic data that serve the needs of research, management, and the public. Data collected as part of this mapping cooperative continue to be released in a series of USGS Open-File Reports and Data Releases https://www.usgs.gov/centers/whcmsc/science/geologic-mapping-massachusetts-seafloor.
Supplemental_Information:
Support for 2022-001-FA was provided to the USGS from the Massachusetts Office of Coastal Zone Management. Approximately 686 linear kilometers of multibeam echosounder data were collected during 13 survey days along tracklines spaced 87 or 52 meters apart. Data were collected using the R/V Rafael, owned and operated by the USGS Woods Hole Coastal and Marine Science Center. Additional information on the field activity is available from https://cmgds.marine.usgs.gov/fan_info.php?fan=2022-001-FA.
  1. How might this data set be cited?
    Andrews, Brian D., 20230309, Multibeam bathymetric data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA using a Teledyne SeaBat Integrated Dual-Head (IDH) T20-P multibeam echosounder (32-bit GeoTIFF, UTM Zone 19N, NAD 83, MLLW Datum, 2-m resolution): data release DOI:10.5066/P9O5G5OT, U.S. Geological Survey, Coastal and Marine Hazards and Resources Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Andrews, Brian D., Baldwin, Wayne E., Worley, Charles R., Moore, Eric M., Nichols, Alex R., Danforth, William W., Foster, David S., Ackerman, Seth D., and Brothers, Laura L., 2023, High-resolution geophysical data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA: data release DOI:10.5066/P9O5G5OT, U.S. Geological Survey, Reston, VA.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Andrews, B.D., Baldwin, W.E., Worley, C.R., Moore, E.M., Nichols, A.R., Danforth, W.W., Foster, D.S., Ackerman, S.D., and Brothers, L.L. 2023, High-resolution geophysical data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA: U.S. Geological Survey data release, https://doi.org/10.5066/P9O5G5OT
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -70.488409
    East_Bounding_Coordinate: -70.268959
    North_Bounding_Coordinate: 41.573653
    South_Bounding_Coordinate: 41.495329
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/63e3e0add34e9fa19a9bb70a?name=2022-001-FA_TeledyneSeaBat_T20P_Bathymetry_2m_browse.jpg (JPEG)
    Thumbnail image of 2-m multibeam echosounder bathymetry data collected within Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 03-Jun-2022
    Ending_Date: 21-Jun-2022
    Currentness_Reference:
    data were collected on the following dates: 20220603-20220607 (Julian day 154-158), 20220610-20220614 (Julian day 161-165), 20220620-20220621 (Julian day 171-172). No usable bathymetry or backscatter data were collected on 20220624 (Julian Day 175).
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: raster digital data
  6. How does the data set represent geographic features?
    1. How are geographic features stored in the data set?
      This is a Raster data set. It contains the following raster data types:
      • Dimensions 4494 x 9084 x 1, type Pixel
    2. What coordinate system is used to represent geographic features?
      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 19N
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -69
      Latitude_of_Projection_Origin: 0
      False_Easting: 500000
      False_Northing: 0
      Planar coordinates are encoded using row and column
      Abscissae (x-coordinates) are specified to the nearest 2.0
      Ordinates (y-coordinates) are specified to the nearest 2.0
      Planar coordinates are specified in meters
      The horizontal datum used is GCS_North_American_1983_2011.
      The ellipsoid used is GRS_1980.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222101.
      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean Lower Low Water (MLLW)
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    Entity_and_Attribute_Overview:
    Data values represent depths referenced to the Mean Lower Low Water (MLLW) tidal datum. Depth range is -1.366 to -42.528 meters.
    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Brian D. Andrews
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey
    Attn: Brian Andrews
    Geographer
    384 Woods Hole Road
    Woods Hole, Massachusetts
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov

Why was the data set created?

The purpose of this raster depth grid is to provide a high-resolution digital elevation model (DEM) of the seafloor in the vicinity of Horseshoe Shoal, Nantucket Sound.

How was the data set created?

  1. From what previous works were the data drawn?
    RAW Teledyne T20-P MULTIBEAM ECHOSOUNDER FILES (source 1 of 1)
    U.S. Geological Survey, Unpublished Material, raw MBES data in Teledyne .s7k format.

    Type_of_Source_Media: disc
    Source_Contribution:
    Multibeam echosounder (MBES) bathymetry and backscatter data were collected using integrated, dual-head Teledyne T20-P sonars. The pair of mills cross transmit and receive arrays were mounted side-by-side within a bracket that oriented them at opposing 30-degree angles (relative to horizontal). The bracket was pole-mounted on the starboard side of the R/V Rafael so that the sonar arrays were oriented athwart ships (primary and secondary arrays facing outward and down to port and starboard, respectively) and located approximately 1.215 m below the waterline when deployed. Vessel navigation and attitude data were acquired using an Applanix POS MV Wavemaster (model 220, V5) configured with two AeroAntenna Technologies GNSS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the after end of the cabin, and the wetpod MRU mounted atop the sonar bracket just aft of the pole. An AML Micro X SV mounted on the sonar bracket monitored sound speed near the sonars during acquisition, and AML-3LGR or Minos X CTDSV profilers were used to collect water column sound speed profiles 3 to 7 times each survey day. The Teledyne SeaBat User Interface (version 5.2.0.1) was used to control the sonars, which were operated in intermediate mode at full power (220 dB), with frequency-modulated pulse at 400 kHz. The range of the 1024 across track beams formed by the sonars were adjusted manually depending on water depth and resulted in combined swath widths of 50 to 300 meters or typically 3 to 6 times the water depth. Data were monitored and recorded using the Teledyne SeaBat User Interface (UI) (version 5.2.0.1) and Hypack/Hysweep (v. 2022). The SeaBat User Interface logged the navigation, attitude, bathymetry, time-series backscatter (using the normalized backscatter datagram), and water column data to s7k format files for each sonar into one, integrated s7k file. The s7k line files were created by the Teledyne UI using the following naming convention: YYYYMMDD_HHMMSS.
  2. How were the data generated, processed, and modified?
    Date: Jun-2022 (process 1 of 3)
    PROCESSING STEP 1: QIMERA DATA PROCESSING.
    Multibeam bathymetry processing within Qimera multibeam processing software (version 2.5.0) during the survey consisted of the following workflow:
    1) A new Qimera project was created with projection information set to Universal Transverse Mercator (UTM) Zone 19N, WGS 84. The s7k files for each Julian day were imported to the project using the Source/add raw sonar files menu.
    2) A Vessel configuration file was created with the linear and angular installation offsets for each T20-P sonar head as well as vendor specified uncertainty values for each of the survey sensors.
    3) Sound Velocity profiles for each day were imported and converted to Qimera using the Source/import/Caris svp menu. Each profile was reviewed for incorrect records using the SVP editor. Incorrect records near the surface or within the water column were flagged using the "reject selection" context menu.
    4) Predicted Tides from the Woods Hole, MA tidal station (id 8447930) for the month of June, were downloaded and imported using the Source/Add Tide Files menu. Predicted tides were referenced to Mean Lower Low Water (MLLW) at 6-minute intervals.
    5) Delayed heave data from the raw POS MV files (.000) were used to update raw sonar lines using the Source/add binary navigation menu function.
    6) The Processing Settings Editor was used to establish the following:
    a) Sound velocity Strategy: nearest in time, Use first entry as raytrace profile.
    b) Position, Motion, and Heading Source Priorities: were set position 1, Motion 1, and Motion 1 respectively.
    c) Vertical Referencing was set to the Woods Hole predicted Tide file.
    d) Blocking filters were set to Across Track = 0-to-80 meters on each sonar head. Colinearity Fail was also selected.
    7)Each raw sonar file was processed using the settings described above.
    8) A preliminary, 2-m resolution dynamic surface (2022-001-FA_2m_Draft) was created and reviewed for inconsistencies and anomalies. The swath editor was used to remove spurious points through manual editing and filter application.
    The contact person for this and all subsequent processing steps below is Brian Andrews. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Brian Andrews
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Data sources produced in this process:
    • 2022-001-FA_TeledyneT20P_Bathymetry_2m_Draft
    Date: Nov-2022 (process 2 of 3)
    PROCESSING STEP 2: APPLY POST PROCESSED SBET FILES AND EDIT SOUNDINGS.
    Post-survey processing within Qimera (version 2.5.0) consisted of the following workflow:
    1) Post-processed navigation, vessel attitude, and GNSS height data from POSPac Smoothed Best Estimate of Trajectory (SBET) files, and post-processed RMS attitude error data from POSPac smrmsg files were used to update each Sonar file using the Source/Add Binary Navigation Files function. The SBET files were referenced using the WGS 84 Ellipsoid (meters).
    2) Once the sbet and smrmsg files were imported for each raw sonar file, the Processing Settings Editor was used to replace the attitude and tide referencing data using the following settings:
    a) Position, Motion, and Heading Source Priorities were superseded by "sbet" file.
    b) Vertical Referencing Method was set to "RTK (Accurate Height)" using the "sbet" file.
    3) A new 2-m resolution dynamic surface was created. Additional editing was conducted using the Swath and 3D editors to minimize inconsistencies and artifacts, and the dynamic surface was recomputed to reflect the changes. Finally, a new 2-m Static Surface was created using the Weighted Moving Average method and a Weighting Diameter of 1 cell. Data sources produced in this process:
    • 2022-001-FA_TeledyneT20P_2m_WGS84
    Date: 03-Jan-2023 (process 3 of 3)
    PROCESSSING STEP 3: EXPORT AND TRANSFORM TO MLLW Tidal Datum.
    The static surface was exported as 2-m per pixel ASCII file referenced to UTM Zone 19N, WGS 84 and WGS 84 ellipsoidal heights, but the desired vertical datum of the final bathymetric surface is the MLLW tidal datum. The National Oceanic and Atmospheric Administration's Vertical Datum Transformation tool (VDatum v. 4.5.1) was used for the transformation. The process required transformation of the horizontal and vertical reference frames from UTM Zone 19, WGS 84 (ITRF 2008) and WGS 84 ellipsoidal heights to UTM Zone 19, NAD83_2011, MLLW (meters) using the GEIOD18 geoid model. The resulting ASCII raster was opened in ArcGIS Pro (v. 3.0) and then exported as a 32-bit floating point GeoTIFF (2022-001-FA_TeledyneT20P_Bathymetry_2m.tif.) using the "Data Export" tool. Data sources produced in this process:
    • 2022-001-FA_TeledyneT20P_Bathymetry_2m.tif
  3. What similar or related data should the user be aware of?
    Baldwin, W.E., Foster, D.S., Barnhardt., W.A., Schwab, W.C., Andrews, B.D., and Ackerman, S.D., 2016, Shallow Geology, Sea-floor Texture, and Physiographic Zones of Vineyard and western Nantucket Sounds, Massachusetts: Open-File Report 2016-1119, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details:
    This previous data release was also published as part of the USGS/CZM cooperative and may be of interest to others because it is directly west of, and overlaps, with the data collected during USGS Field Activity 2022-001-FA.
    Pendleton, E.A., Andrews, B.D., Ackerman, S.D., Danforth, W.W., and Foster, D.S., 2014, High-resolution geophysical data collected aboard the U.S. Geological Survey research vessel Rafael to supplement existing datasets from Buzzards Bay and Vineyard Sound, Massachusetts: Open-File Report 2013–1020, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details:
    This previous data release was also published as part of the USGS/CZM cooperative and may be of interest to others because it is directly west of, and overlaps, with the data collected during USGS Field Activity 2022-001-FA.
    Andrews, B.D., Ackerman, S.D., Baldwin, W.E., Foster, D.S., and Schwab, W.C., 2013, High-resolution geophysical data from the inner continental shelf at Vineyard Sound, Massachusetts: Open-File Report 2012–1006, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    Other_Citation_Details:
    This previous data release was also published as part of the USGS/CZM cooperative and may be of interest to others because it is directly west of, and overlaps, with the data collected during USGS Field Activity 2022-001-FA.

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

  1. How well have the observations been checked?
  2. How accurate are the geographic locations?
    Navigation data were acquired using the WGS 84 coordinate system with an Applanix POS MV Wavemaster (model 220, V5), which utilizes multiple GNSS satellite and acceleration data from a Motion Reference Unit (MRU) and GNSS azimuthal heading. The POS MV was configured with two AeroAntenna Technologies GNSS antennas located at either end of a 2-m baseline, which was oriented athwartship and mounted atop the after end of the cabin. DGPS positions were obtained from the primary antenna located on the starboard end of the baseline, and the positional offsets between the antenna and the navigational reference point (the POS MV IMU) were accounted for in the Applanix POSView (version 11.00) acquisition software. DGPS positions are horizontally accurate to 0.5 - 2 meters, but accuracy can increase to less than 10 cm after post-processing with Applanix POSPac (version 8.8).
  3. How accurate are the heights or depths?
    Vertical accuracy of the raw data based on system specifications may be approximately 1 percent of water depth (ranging from 0.013 to .425 meters based on the water depth range of 1.3 to approximately 42.5 meters within the survey area). The Applanix Wavemaster POS MV Attitude and Positioning system, used to correct for vessel roll, pitch, heave, and yaw, has a theoretical vertical accuracy of a few mm. Post-Processed Kinematic (PPK) GPS height corrections (from Applanix POSPac smoothed best estimate of trajectory (SBET) files) were used to reference soundings to the World Geodetic System 1984 (WGS 84) ellipsoid and remove water level fluctuations during the survey. Forty-six sound speed profiles acquired with AML-3LGR or Minos X CTDSV sound velocity profilers were used during processing to minimize acoustic refraction artifacts in the bathymetry data.
    Cross line and junction analysis was calculated using line 20220603_200041. The median difference between overlapping soundings was 0.004 meters which meets IHO s-44 Order 1 standards.
    Additionally, uncertainty associated with the vertical transformation of the bathymetric grid from WGS 84 (ITRF 2008) ellipsoidal heights to the Mean Lower Low Water tidal datum is 0.1240137 meters as calculated by the VDatum tool (v. 4.5.1).
  4. Where are the gaps in the data? What is missing?
    Data collected along sonar calibration lines and cross lines used for data quality checks are not included in this grid, however, the trackline navigation for all lines are included in the 2022-001-FA_TeledyneT20P_Tracklines.shp shapefile included in this publication.
  5. How consistent are the relationships among the observations, including topology?
    This grid represents processed data collected using a Teledyne SeaBat Integrated Dual-Head (IDH) T20-P multibeam echosounder (MBES) gridded at 2-m resolution. Quality control and data processing were conducted to remove spurious points and reduce sound speed artifacts (refraction) using Qimera (v. 2.5) multibeam processing software.

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 re-distributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey as the originator of the dataset. These data are not to be used for navigation.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey - ScienceBase
    Denver Federal Center
    Denver, CO

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? Multibeam bathymetric data collected in Nantucket Sound Massachusetts in the vicinity of Horseshoe Shoal, during USGS Field Activity 2022-001-FA using a dual-head Teledyne T20-P multibeam echosounder: includes the GeoTIFF image 2022-001-FA_TeledyneT20P_Bathymetry_2m.tif, the browse graphic 2022-001-FA_TeledyneT20P_Bathymetry_2m_browse.jpg, and Federal Geographic Data Committee (FGDC) Content Standards for Digital Geospatial Metadata (CSDGM) metadata file (2022-001-FA_TeledyneT20P_Bathymetry_2m_meta.xml).
  3. What legal disclaimers am I supposed to read?
    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), and have been processed successfully on a computer system at the USGS, no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/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?
  5. What hardware or software do I need in order to use the data set?
    To utilize these data, the user must have software capable of uncompressing the zip file and viewing GeoTIFF files.

Who wrote the metadata?

Dates:
Last modified: 09-Mar-2023
Metadata author:
U.S. Geological Survey
Attn: Brian Andrews
Geographer
384 Woods Hole Rd.
Woods Hole, MA

(508) 548-8700 x2348 (voice)
(508) 457-2310 (FAX)
whsc_data_contact@usgs.gov
Contact_Instructions:
The metadata contact email address is a generic address in the event the person is no longer with the USGS.
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/SB_data_release/DR_P9O5G5OT/2022-001-FA_TeledyneSeaBat_T20P_Bathymetry_2m_meta.faq.html>
Generated by mp version 2.9.51 on Fri Mar 10 09:59:13 2023