Sound velocity profile locations, images, and processed text collected by the U.S. Geological Survey in the vicinity of Muskeget Channel, MA, 2010 (Geographic, WGS 84, Esri Shapefile, PNG images, and text files)

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Frequently anticipated questions:

What does this data set describe?

Title:
Sound velocity profile locations, images, and processed text collected by the U.S. Geological Survey in the vicinity of Muskeget Channel, MA, 2010 (Geographic, WGS 84, Esri Shapefile, PNG images, and text files)
Abstract:
These data were collected in a collaboration between the Woods Hole Oceanographic Institution and the U.S. Geological Survey (USGS). The primary objective of this program was to collect baseline bathymetry for Muskeget Channel, Massachusetts, and identify areas of morphologic change within and around the channel. Repeat surveys in select areas were collected one month apart to monitor change. These data were collected to support an assessment of the effect on sediment transport that a tidal instream energy conversion facility would have within Muskeget Channel. Accurate data and maps of sea-floor topography are important first steps in monitoring bedform migration, fish habitat, marine resources, and environmental changes due to natural or human impacts. The data include high-resolution bathymetry, acoustic-backscatter intensity, sound velocity in water, and navigation data. These data were collected during two surveys between October 2010 and November 2011 onboard the research vessel (RV) Rafael using an SEA Ltd. SwathPlus interferometric sonar (234 kilohertz). More information about the cruise can be found on the Woods Hole Coastal and Marine Science Center field activity Web page at <http://woodshole.er.usgs.gov/operations/ia/public_ds_info.php?fa=2010-072-FA>
  1. How should this data set be cited?

    U.S. Geological Survey, 2014, Sound velocity profile locations, images, and processed text collected by the U.S. Geological Survey in the vicinity of Muskeget Channel, MA, 2010 (Geographic, WGS 84, Esri Shapefile, PNG images, and text files): Open-File Report 2012-1258, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Pendleton, Elizabeth A., Denny, Jane F., Danforth, William W., Baldwin, Wayne E., and Irwin, Barry J., 2014, High-Resolution Swath Interferometric Data Collected within Muskeget Channel, Massachusetts: Open-File Report 2012-1258, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -70.436390
    East_Bounding_Coordinate: -70.410363
    North_Bounding_Coordinate: 41.419526
    South_Bounding_Coordinate: 41.308611

  3. What does it look like?

    http://pubs.usgs.gov/of/2012/1258/GIS_catalog/svps/svp_thumb.png (PNG)
    Woods Hole Coastal and Marine Science Center sound velocity profile locations within Muskeget Channel, MA
    http://pubs.usgs.gov/of/2012/1058/GIS_catalog/svps/svp_image.png (PNG)
    Woods Hole Coastal and Marine Science Center sound velocity profile image within Muskeget Channel, MA

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

    Calendar_Date: 12-Oct-2010
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: raster and vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Entity point (11)

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

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      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: Local surface
      Depth_Resolution: 0.1
      Depth_Distance_Units: meters
      Depth_Encoding_Method: Attribute values

  7. How does the data set describe geographic features?

    XYsvp_locs
    Sound velocity profile locations (Source: U.S. Geological Survey)

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    x
    Easting coordinate in UTM Zone 19 meters, WGS84 (Source: U.S. Geological Survey)

    Range of values
    Minimum:379775.1
    Maximum:382000
    Units:meters
    Resolution:1

    y
    Northing coordinate in UTM Zone 19 meters, WGS84 (Source: U.S. Geological Survey)

    Range of values
    Minimum:4574011.5
    Maximum:4586325.6
    Units:meters
    Resolution:1

    z
    depth of water at profile location based on fathometer reading in HYPACK. (Source: U.S. Geological Survey)

    Range of values
    Minimum:6.5
    Maximum:20
    Units:meters
    Resolution:0.1

    cast
    Name of velocity profile used to distinguish between casts. (Source: U.S. Geological Survey)

    Sequential numbers used to distinguish sound velocity casts.

    jd
    Julian day data were collected (Julian day is the integer number representing the interval of time in days since January 1 of the year) (Source: U.S. Geological Survey)

    Range of values
    Minimum:214
    Maximum:341
    Units:day
    Resolution:1

    UTC
    Coordinated Universal Time of sound velocity cast (in the format: hhmm) (Source: U.S. Geological Survey)

    Range of values
    Minimum:1225
    Maximum:1959
    Units:time
    Resolution:minute

    Entity_and_Attribute_Detail_Citation: U.S. Geological Survey
    Entity_and_Attribute_Overview:
    Although the PNG images and text format data files do not have coordinates associated with the data themselves, they are related to the SVP locations (shapefile: XYsvp_locs.shp) by the cast number in the attribute table. Although the header was removed on the text files during processing, the first column of data is water depth in meters below the surface and column 2 is speed of sound in meters per second.

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?

    Elizabeth A. Pendleton
    U.S. Geological Survey
    Geologist
    384 Woods Hole Road
    Woods Hole, MA 02543-1598
    USA

    508-548-8700 x2259 (voice)
    508-457-2310 (FAX)
    ependleton@usgs.gov

Why was the data set created?

This dataset is used to display the raw data, profile image, and locations of sound velocity data collected during a USGS cruise within the vicinity of Muskeget Channel, MA. The information contained within the sound velocity profile is needed to adequately account for refraction artifacts that may be present within raw swath bathymetric data. This dataset can hyperlink to graphs of the sound velocity profile at each station location, as well as location in easting and northing (UTM, Zone 19N, WGS84, meters), time of day and date.

How was the data set created?

  1. From what previous works were the data drawn?

    USGS (source 1 of 1)
    U.S. Geological Survey.

    Type_of_Source_Media: disc
    Source_Contribution:
    Sound velocity profiles are acquired in order to measure the speed of sound in the water column during survey operations. This information is used to help correct any refraction artifacts that may be present within the swath bathymetric data due to unaccounted for changes in the speed of sound throughout the water column.

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

    Date: 2007 (process 1 of 3)
    Profiles were collected at least once during each survey day, and multiple times per day when the data suggested significant stratification within the water column. Sound velocity casts were collected using an Applied Microsystems SV Plus v2 instrument (see <http://www.amloceanographic.com> for details).
    At each station, the SV plus 2 was hand deployed and slowly lowered to the seafloor. The SV plus v2 was monitored by a member of the science party and as the instrument made contact with the seafloor, the position (i.e. location) and depth (based on fathometer) was recorded in the lab using HYPACK navigation software. The position was then manually recorded within the cruise log and SWATHplus acquisition software. Upon recovery, the SV plus was connected to an onboard computer via serial port in order to download data using the SV plus v2 communications software, SmartTalk. Raw SVP data (text format) were edited using awk to remove the header information and remove data columns except water depth (pressure) and speed of sound

    Person who carried out this activity:

    Elizabeth A. Pendleton
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700x2259 (voice)
    (508) 457-2310 (FAX)
    ependleton@usgs.gov

    Date: 2013 (process 2 of 3)
    The data were then exported in text format and imported to MATLAB (version R2011a). Graphs of the sound velocity profile (Pressure vs. speed of sound) at each station were created within MATLAB and exported as *.png files. A MATLAB script is included in the svp_data.zip file that creates PNG image profiles from the sound velocity text files.

    Person who carried out this activity:

    Elizabeth A. Pendleton
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700x2259 (voice)
    (508) 457-2310 (FAX)
    ependleton@usgs.gov

    Date: 2013 (process 3 of 3)
    The location of each sound velocity profiles recorded in the survey log in eastings and northings (UTM, Zone 19N, meters, WGS84) was saved to a comma-separated value file (*.txt) along with station number, water depth at station, julian day and time, and survey id. The comma-separated text file was then imported to ArcMap 9.3 using 'Add XY data' and saved as points (UTM WGS84 Zone 19N) in the Esri shapefile format. Finally, the data were reprojected from UTM Zone 19N, WGS84 to GCS WGS84 using ArcToolbox

    Person who carried out this activity:

    Elizabeth A. Pendleton
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2259 (voice)
    (508) 457-2310 (FAX)
    ependleton@usgs.gov

  3. What similar or related data should the user be aware of?

    Poppe, L.J., McMullen, K.Y., Foster, D.S., Blackwood, D.S., Williams, S.J., Ackerman, S.D., Moser, M.S., and Glomb, K.A., 2010, Geological Interpretation of the Sea Floor Offshore of Edgartown, Massachusetts: Open-File Report 2009-1001, U.S. Geological Survey, Reston, VA.

    Online Links:

    Denny, J.F., Danforth, W.W., Foster, D.S., and Sherwood, C.R., 2009, Geophysical Data Collected off the South Shore of Martha's Vineyard, Massachusetts: Open-File Report 2008-1288, U.S. Geological Survey, Reston, VA.

    Online Links:

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 data were acquired with a Communications Systems International (CSI), Inc. LGBX Pro receiver and recorded with HYPACK (www.hypack.com). The CSI received positions from a DGPS antenna located on the port, aft roof of the R/V Rafael cabin. Ship location was used for the sound velocity deployments. The SV plus v2 sound velocity profiler was hand deployed. Once the system reached bottom, positions were read from HYPACK and stored in the survey log. DGPS accuracy is 1 to 3 meters, depending on the distance from a US Coast Guard coastal repeater station. However, offsets from the location of hand-deployment and the DGPS antenna were not measured, and the ship is allowed to drift during deployment which can last several minutes depending on water depth. The horizontal accuracy of the sound velocity locations is considered to be +/- 50 meters.

  3. How accurate are the heights or depths?

    Water depth of the sound velocity profile location is recorded from the fathometer. Assumed vertical accuracy of the shipboard fathometer on the R/V Rafael is about 0.25 meters. However, vessel drift during SVP deployment and recovery could add an additional meters of change in water depth at the location of deployment. Water depth recorded in the shapefile attribute field should be considered an approximation of water depth at the location of SVP deployment. Water depth in the sound velocity profiles is extracted from the recorded sound velocity profile after recovery. Depth (as pressure in dbars or meters) is recorded as the sound velocity profiler is lowered through the water column and downloaded after the instrument is recovered. Data are stored in ASCII text files. Depth values in the profile text and images should be accurate to within 1 meter.

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

    All sound velocity profiles collected during 2010-072-FA are included here as text, images, and a shapefile of the locations.

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

    All sound velocity profiles were acquired with the same instrument; an Applied Microsystems SV plus v2.

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. Please recognize the U.S. Geological Survey as the originator of the dataset.

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

    Elizabeth A. Pendleton
    U.S. Geological Survey
    Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700x2259 (voice)
    (508) 457-2310 (FAX)
    ependleton@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?

    This zip file contains data available in Environmental Systems Research Institute (Esri) point shapefile format, PNG image format, and text. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the shapefile. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from Esri at www.esri.com. The PNG image data can be viewed with any image viewing software and text data that can be viewed with any text editor.

Who wrote the metadata?

Dates:
Last modified: 06-Jan-2014
Metadata author:
Elizabeth Pendleton
U.S. Geological Survey
Geologist
384 Woods Hole Rd.
Woods Hole, MA 02543-1598

(508) 548-8700x2259 (voice)
(508) 457-2310 (FAX)
ependleton@usgs.gov

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

Generated by mp version 2.9.27 on Mon Jun 09 15:06:16 2014