VS_BATH5M_V2: Revised 5 meter ArcRaster grid of bathymetry acquired using a SEA Ltd. SWATHplus-M interferometric sonar offshore of Massachusetts within Vineyard Sound by the U.S. Geological Survey in 2009, 2010, and 2011 (Esri BINARY GRID, UTM 19N, WGS84).

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

Frequently-anticipated questions:


What does this data set describe?

Title:
VS_BATH5M_V2: Revised 5 meter ArcRaster grid of bathymetry acquired using a SEA Ltd. SWATHplus-M interferometric sonar offshore of Massachusetts within Vineyard Sound by the U.S. Geological Survey in 2009, 2010, and 2011 (Esri BINARY GRID, UTM 19N, WGS84).
Abstract:
These data were collected under a cooperative agreement with the Massachusetts Office of Coastal Zone Management (CZM) and the U.S. Geological Survey (USGS), Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center (WHSC). Initiated in 2003, the primary objective of this program is to develop regional geologic framework information for the management of coastal and marine resources. Accurate data and maps of sea-floor geology are important first steps toward protecting fish habitat, delineating marine resources, and assessing environmental changes due to natural or human impacts. The project is focused on the inshore waters of coastal Massachusetts, primarily in water depths of 3-30 meters deep. Data collected for the mapping cooperative have been released in a series of USGS Open-File Reports (<http://woodshole.er.usgs.gov/project-pages/coastal_mass/html/current_map.html>). The data collected in the study area located in Vineyard Sound Massachusetts includes high-resolution geophysics (bathymetry, backscatter intensity, and seismic reflection). The data were collected during three separate surveys conducted between 2009 and 2011and cover approximately 340 square kilometers of the inner continental shelf. More information about the individual USGS surveys conducted as part of the Vineyard Sound project can be found on the Woods Hole Coastal and Marine Science Center Field Activity webpage:

2009-002-FA: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2009-002-FA>

2010-004-FA: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-004-FA>

2011-004-FA: <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2011-004-FA>

  1. How should this data set be cited?

    U.S. Geological Survey, 2014, VS_BATH5M_V2: Revised 5 meter ArcRaster grid of bathymetry acquired using a SEA Ltd. SWATHplus-M interferometric sonar offshore of Massachusetts within Vineyard Sound by the U.S. Geological Survey in 2009, 2010, and 2011 (Esri BINARY GRID, UTM 19N, WGS84).: Open-File Report 2012-1006, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, Massachusetts.

    Online Links:

    This is part of the following larger work.

    Andrews, Brian D. , Ackerman, Seth D. , Baldwin, Wayne E. , Foster, David S. , and Schwab, William C. , 2014, High-Resolution Geophysical Data from the Inner Continental Shelf: Vineyard Sound, Massachusetts: Open-File Report 2012-1006, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -71.037126
    East_Bounding_Coordinate: -70.421882
    North_Bounding_Coordinate: 41.545884
    South_Bounding_Coordinate: 41.262143

  3. What does it look like?

    <http://pubs.usgs.gov/of/2012/1006/GIS/browse_jpg/vs_bath5m_v2.jpg> (JPEG)
    Black and white thumbnail image of bathymetry collected in the Vineyard Sound Massachusetts survey area.

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

    Beginning_Date: 02-Jun-2009
    Ending_Date: 17-May-2011
    Currentness_Reference:
    ground condition of individual surveys on the following dates: 2009062-20090603; 20100521-20100604; 20110507-20110509; 20110514-20110517

  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 6100 x 10168 x 1, type Grid Cell

    2. What coordinate system is used to represent geographic features?

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 19
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -69.000000
      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 5.000000
      Ordinates (y-coordinates) are specified to the nearest 5.000000
      Planar coordinates are specified in meters

      The horizontal datum used is D_WGS_1984.
      The ellipsoid used is WGS_1984.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257224.

      Vertical_Coordinate_System_Definition:
      Depth_System_Definition:
      Depth_Datum_Name: Mean lower low water
      Depth_Resolution: 0.1 meters
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Explicit depth coordinate included with horizontal coordinates

  7. How does the data set describe geographic features?

    Value
    Depth in meters below mean lower low water (Source: Esri)

    Range of values
    Minimum:-37.9
    Maximum:-3.61
    Units:meters

    Entity_and_Attribute_Overview:
    Bathymetric depth values in Esri ArcRaster format. Data values represent depth in meters referenced to mean lower low water (MLLW).
    Entity_and_Attribute_Detail_Citation: ESRI


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?

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598
    USA

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


Why was the data set created?

This composite bathymetric grid is used to define the morphology of the seafloor for regional geological analysis. This grid includes the bathymetry collected by the USGS during surveys 2009-002-FA, 2010-004-FA, and 2011-004-FA in Vineyard Sound Massachusetts at 5 meter resolution.


How was the data set created?

  1. From what previous works were the data drawn?

    (source 1 of 1)
    Source_Contribution:
    Sonar Configuration: Bathymetry data were acquired using a Systems Engineering and Assessment Ltd. (SEA) SWATHplus-M interferometric sonar operating at 234 kHz and variable range (increased or decreased manually depending on water depth.) During surveys 2009-002-FA and 2010-004-FA, the sonar transducers were mounted on a rigid pole from the starboard side of the M/V Megan T. Miller about 2.4 m below the water line. During survey 2011-004-FA, the sonar transducers were mounted on a rigid pole from the port side of the M/V Scarlett Isabella about 2.17 m below the water line. The system was operated with a transmit power of 80 percent, a transmit length of 12 cycles (2009-002-FA and 2010-004-FA) or 43 cycles (2011-004-FA), 3072 samples per channel (2009-002-FA), or 4096 samples per channel (2010-004-FA and 2011-004-FA). Survey lines were run at an average speed of 5 knots and were spaced 50-100 m apart to obtain overlapping swaths of data and full coverage of the seafloor. Speed of Sound: Sound-velocity profiles were collected approximately every 2 hours by hand casted Applied MicroSystems SV Plus sound velocimeter (2009-002-FA), or an ODIM MVP30 moving vessel profiler (2010-004-FA and 2011-004-FA). Tides: During post-processing, soundings were referenced to Mean Lower Low Water (MLLW) using 1 minute averaged RTK-GPS sea-surface elevation data.

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

    Date: 2009 (process 1 of 6)
    Step 1:Process GPS Tides Data for all three surveys: Depths were corrected to Mean Lower Low Water (MLLW) using the 1 second RTK-GPS heights from the GPS receiver mounted over the SWATHplus-M sonar head. Two scripts were used and described below getNovatelTides: extracts the "TID" record from each Hypack line file parseHypackNovatelTides.awk: calculates the average TID value for every two minutes. Each day was appended to a master tide file in CARIS format ("SurveyName"Master.tid) and merged into the line files in Processing Step #3 below.

    Person who carried out this activity:

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598
    USA

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

    Date: 2009 (process 2 of 6)
    Step 2: Raw to Processed Conversion for all three surveys: Each raw SWATHplus bathymetric sonar file (sxr) was converted to a SWATHplus processed file (sxp) using SEA SWATHplus Swath Processor (ver. 3.06 for 2009-002-FA, 2010-004-FA, and 3.07 for 2011-004-FA). During the conversion process, sound velocity profiles were used to minimize potential refraction artifacts from fluctuations in the speed of sound within the water column. NOAA Predicted tides were used during the conversion process, however, these were updated and merged with the GPS tide data described in Step 1 above. Bathymetric filters that were typically used in SWATH Processor acquisition software included a low amplitude (100%), range (0-4m), box (3-50m depth, 1.5-75m horizontal), median (window size 5), along track 1 (depth difference of 5-m, window size 5-m, and learn rate of 0.7), along track 2 (depth difference of 1.5-m, window size 1m, and learn rate of 0.9), and a mean filter (0.25m). These represent the typical parameters used for the majority of the USGS survey although the values may have been adjusted slightly for specific parts of the survey area.

    Person who carried out this activity:

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA 02543-1598
    USA

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

    Date: 2009 (process 3 of 6)
    Step 3: SWATHplus to CARIS Conversion: A new CARIS HIPS project (ver. 6.1 for 2009-002-FA and 7.1 for 2010-004-FA and 2011-004-FA) was created for each of the three surveys with projection information set to Universal Transverse Mercator (UTM) Zone 19, WGS84. Each SWATHplus processed file (sxp) was imported to the new CARIS project using the Import/Conversion Wizard. The line files for each Julian day were merged with the Master tide file produced in Step 1 (09002_TID_master.tid, 10004_RTK_Tides_VS_Master.tid, 11004_Master.tid) to reference each line to Mean Lower Low Water. A 5 meter resolution Bathymetric and Statistical Error (BASE) Surface was created from the files for each Julian day. The BASE surface for each day was reviewed for any inconsistencies or data anomalies. Navigation was edited as needed using the navigation editor tool in CARIS. Filters were applied to each line including beam to beam slopes (2 degrees), and across track distance (50-60 m). Each line was edited using range filters maximize across-track coverage and reduce data gaps where possible. The CARIS refraction editor was used to adjust the speed of sound in some cases to flatten out the depth profiles produced by localized variations in speed of sound through the water column.

    Person who carried out this activity:

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA 02543-1598
    USA

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

    Date: 14-Feb-2014 (process 4 of 6)
    Step 4: Merge zone tides to Southwest portion of survey area to replace RTK tides.

    The RTK signal from repeater station located at Gay Head was not received by the survey vessel for several hours on several days between May 22 and May 29 2010 during USGS Field Activity 2010-004-FA aboard the M/V Megan T. Miller. Earlier attempts to interpolate tide values for missing times were not effective. Instead, USGS requested and received a zone tidal model from the National Oceanic and Atmospheric Administration in December of 2013. Tides were delivered to USGS on 10 Feb and applied only to lines L114F1-L200f1 and including Tie1-Tie10f2 (JD141-JD149). The zone tidal model used verified tides at six minute intervals from three NOAA Tide stations Newport, RI (#84526600), Woods Hole, MA (#8447930), and Nantucket MA, (#8449130). The NOAA Zone Definition File was loaded into HIPS (ver 8.1.6) and merged with Lines L114f1-L200f1.

    Person who carried out this activity:

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA 02543-1598
    USA

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

    Date: 20-Feb-2014 (process 5 of 6)
    Step 5: Combine HDCS files for all three surveys: Make a new CARIS HIPS project that contains only those processed line files from all three surveys that will be used for the final bathymetric grid. A 5 meter BASE surface was created (VS_BathAll_5m) covering the spatial extent of all three surveys within Vineyard Sound. Small no data holes within the base surface were filled in using the "Interpolate Base Surface" function in CARIS. Each cell in the grid is examined to determine if it contains a pixel value. If the node does not contain a value, the 5 neighboring cells are examined to calculate a value for the empty cell. The no data value is replaced with an interpolated value if 6 of the surrounding cells have a pixel value. The "Interpolate Base Surface" was run twice on the input grid. Nevertheless, some "No data" values (data gaps) remain in the final grid (VS_5m5x5), where the gaps are greater than these thresholds.

    Person who carried out this activity:

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA 02543-1598
    USA

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

    Data sources produced in this process:
    • VS_BathAll_5mzdf.csar

    Date: 20-Feb-2014 (process 6 of 6)
    Step 6: CARIS to ArcInfo Conversion: The 5 meter resolution CARIS BASE (VS_5m5x5zdf.csar) surface was exported out of CARIS as a Bathymetric Attributed Grid (BAG) file and imported to Interactive Visualization Systems (IVS) Fledermaus (ver 7.3) using the "import gridded data" function and converted to an interim IVS Digital Terrain Model (DTM) and geo file (VS_Bathv25m.dtm, .geo). The DTM file was then converted to ArcGIS (ver. 9.3) as a 32-bit floating point ArcRaster grid.(vs_bath5m_v2) using the "transfer bathy raster" tool under the DTM Tool menu. The projection information was defined as UTM Zone 19, WGS_84 for the final grid using the ArcToolbox "Define Projection" tool (ver. 9.3.1).

    Person who carried out this activity:

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@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?

  2. How accurate are the geographic locations?

    Differential Global Positioning System (DGPS) navigation was used to determine the horizontal position (x, and y coordinates) of the GPS antenna mounted above the SWATHplus-M transducers with sub-meter accuracy. A motion reference unit (Coda Octopus F180) was mounted directly above the sonar transducers and continuously measured vertical displacement (heave) and attitude (pitch and roll) of the vessel during data acquisition. Horizontal offsets between navigation and attitude antennas and the SWATHplus-M transducers were applied during acquisition in the configuration files for the SWATHplus-M and Coda Octopus F180 software. Differential corrections were transmitted to the survey vessel by cellular modem and VHF radio from the base station established at the USGS Marine Operations Facility in Falmouth, MA.

  3. How accurate are the heights or depths?

    A motion reference unit (Coda Octopus F180) was mounted directly above the sonar transducers and continuously measured vertical displacement (heave) and attitude (pitch and roll) of the vessel during data acquisition. Vertical offsets between navigation and attitude antennas and the SWATHplus-M transducers were applied during acquisition in the configuration files for the SWATHplus-M and Coda Octopus F180 software. Vertical accuracy of the raw data may approximate 1 percent of water depth, based on SWATHplus interferometric sonar system specifications, which translates to 0.1 to 0.37 meters within the Vineyard Sound survey area. Real Time Kinematic (RTK)-GPS was used to continuously measure changes in sea-surface elevations relative to the Mean Lower Low Water (MLLW)datum with decimeter-scale accuracies. Tide-correction was applied during post-processing (see process steps). Tide corrections using zone tidal model offsets were applied to portions of 2010-004-FA because the RTK signal was interrupted from 22 to 29 May, 2010. The vertical accuracy of these lines is dependent on the observed data from the three tide stations which NOAA publishes as +/- 1.6 cm from Massachusetts to the Gulf of Maine. See Table 3 at NOAA VDatum website <http://vdatum.noaa.gov/docs/est_uncertainties.html#estData>

    Refraction artifacts were minimized by sound velocity profiles throughout the survey area to model the spatial and temporal variability of sound velocity structure of the water column. Changes in vessel draft due to fuel and water usage were not considered.

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

    This grid does not include all bathymetric data collected in the Vineyard Sound survey area. Bathymetry data collected along transit lines, seismic-reflection tie lines and other sections of lines of poor quality were excluded from this grid. Survey lines not included in this grid are: 2009-002-FA L63f1, L64f1, L74f1 2010-004-FA Patch2_1- Patch2_7, TIE8F1-TIE20F1, L286F1 2011-004-FA: Patch1-Patch7, L130F1, TIE1, TIE8-TIE15.

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

    Any spurious data points were removed during processing. Portions of this grid were interpolated to fill small gaps that occurred between adjacent bathymetric survey lines; although interpolation did not fill all gaps. Tide corrections using a zone tide model were applied to the following lines from 2010-004-FA and supersede the previous RTK tide corrections (ver 1.0) L114f1- L200F1, between julian day 141 and julian day 149.


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:
These data are not for navigational use. Public domain data from the U.S. Government are freely redistributable with proper metadata and source attribution. Please recognize the U.S. Geological Survey (USGS) as the source of this information.

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

    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA 02543
    USA

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

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  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. Any use of trade, product, or firm 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?

    These data are available as an ArcInfo 32-bit floating point binary grid in Environmental Systems Research Institute (Esri) format. The grid consists of two folders, one with the "grid name", and one "info" folder. The two folders for each grid are compressed into one file using WinZip (ver. 14.0) software. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing an Esri ArcRaster grid. The two folders for each grid must be uncompressed to the same folder. If during the process of extracting multiple grids in WinZip format to the same folder, the user is prompted by WinZip software to "overwrite existing files" in the info folder select the "yes" option because the same info folder is included in the other gridded datasets.


Who wrote the metadata?

Dates:
Last modified: 09-Apr-2014
Metadata author:
Brian Andrews
U.S. Geological Survey
Geographer
384 Woods Hole Rd.
Woods Hole, MA 02543-1598
USA

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

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:


Generated by mp version 2.8.25 on Wed Apr 09 10:27:21 2014