Buzzards Bay: Polygon boundaries for source data of a continuous bathymetry and topography terrain model of the Massachusetts coastal zone and continental shelf: (Esri polygon shapefile, Geographic, NAD 83).

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Frequently anticipated questions:


What does this data set describe?

Title:
Buzzards Bay: Polygon boundaries for source data of a continuous bathymetry and topography terrain model of the Massachusetts coastal zone and continental shelf: (Esri polygon shapefile, Geographic, NAD 83).
Abstract:
Integrated terrain models covering 16,357 square kilometers of the Massachusetts coastal zone and offshore waters were built to provide a continuous elevation and bathymetry terrain model for ocean planning purposes. The area is divided into the following four geographical areas to reduce file size and facilitate publishing: Massachusetts Bay from the Massachusetts-New Hampshire border south to Provincetown and Scituate and east to Stellwagen Bank; Cape Cod Bay from Provincetown to Scituate and south to Hyannis; Buzzards Bay from the Cape Cod Canal southwest to the State border including the Elizabeth Islands and extending north to Fall River and Mount Hope Bay; and Nantucket and Vineyard Sounds, from Hyannis south to the border of the Massachusetts Coastal zone approximately 8 kilometers south of Nantucket. A Triangulated Irregular Network was created from public-domain bathymetric and LiDAR data using the ArcGIS terrain-model framework and then interpolated into a 32-bit GeoTiff of 10 meter resolution. The grids for each of the four geographical areas are referenced to the Universal Transverse Mercator, Zone 19, North American Datum of 1983 coordinate system, and the North American Vertical Datum of 1988. A polygon shapefile recording the source datasets accompanies each of the four grids.
Supplemental_Information:
This shapefile should be used in conjunction with "BuzzBay_10m.tif" to understand the collection date, and spatial resolution of the source data are variable and should be considered when using this raster for analysis at fine scales. The attribute table of the “BuzzBay_Source.shp” provides details about the collection date, and web address of the source data.
  1. How might this data set be cited?
    U.S. Geological Survey, 2018, Buzzards Bay: Polygon boundaries for source data of a continuous bathymetry and topography terrain model of the Massachusetts coastal zone and continental shelf: (Esri polygon shapefile, Geographic, NAD 83).: data release DOI:10.5066/F72806T7, 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., Baldwin, Wayne E., Sampson, Daniel W., and Schwab, William C., 2018, Continuous bathymetry and elevation models of the Massachusetts coastal zone and continental shelf: data release DOI:10.5066/F72806T7, U.S. Geological Survey, Reston, Virginia.

    Online Links:

    Other_Citation_Details:
    Suggested citation: Andrews, B.D., Baldwin, W.E., Sampson, D.W., and Schwab, W.C., 2018, Continuous bathymetry and elevation models of the Massachusetts coastal zone and continental shelf: U.S. Geological Survey data release, https://doi.org/10.5066/F72806T7.
  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -71.353829
    East_Bounding_Coordinate: -70.538208
    North_Bounding_Coordinate: 41.875025
    South_Bounding_Coordinate: 41.359169
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5a4649d5e4b0d05ee8c05489?name=BuzzBaySource.jpg (JPEG)
    Image of source data boundaries for terrain model of Buzzards Bay. File is located in the compressed zip file.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 1934
    Ending_Date: 2015
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: Vector Digital Data Set (Polygon)
  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):
      • GT-polygon composed of chains (36)
    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 0.000001. Longitudes are given to the nearest 0.000001. Latitude and longitude values are specified in Decimal degrees. The horizontal datum used is D_North_American_1983.
      The ellipsoid used is GRS 1980.
      The semi-major axis of the ellipsoid used is 6378137.0.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    BuzzBay_Source
    Table containing attribute information associated with the data set. (Source: USGS)
    FID
    Internal feature number. (Source: Esri)
    Range of values
    Minimum:0
    Maximum:35
    Shape
    Feature geometry. (Source: Esri) Coordinates defining the features.
    Source
    Simplified name of the survey used as input data using either the agency acronym, and date, or in just the survey ID (NOAA). (Source: USGS) character set
    SurvYear
    The year the survey was conducted, in some cases, the source grid included data collected during several years. In these cases, the SurvYear is the first year of the multiple surveys which are documented in the metadata for the"BuzzBay_10m.tif" (Source: USGS)
    Range of values
    Minimum:1934
    Maximum:2015
    Units:Year
    PubLink
    URL to published data files and metadata for each survey. For LiDAR datasets, this is the url where the laz files were downloaded. (Source: USGS) character set
    SourceType
    Sensor or method used to collect the data (Source: Producer defined)
    ValueDefinition
    Echosounderrefers to a digital sounding device and can include echosounders
    LiDARLIght Detection and Range
    MultibeamMultibeam Sonar
    SwathInterferometric Sonar
    Swath/MultibeamSource data used a combination of both swath interferometric, and multibeam sonars.
    Lead Linemanual sounding device
    SHAPE_Leng
    Length of the polygon feature in meters calculated in the feature class using UTM Zone 19 meters NAD 83, before it was exported as shapefile. (Source: Esri)
    Range of values
    Minimum:2641.68
    Maximum:1398575.75
    Units:meters
    SHAPE_Area
    Area of feature in meters squared calculated in the feature class using UTM Zone 19 meters NAD 83, before exporting to shapefile. (Source: Esri)
    Range of values
    Minimum:199562.58
    Maximum:462749399.39
    Units:meters squared

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • U.S. Geological Survey
  2. Who also contributed to the data set?
    Please recognize the U.S. Geological Survey (USGS) as the source of this information.
  3. To whom should users address questions about the data?
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd.
    Woods Hole, MA
    USA

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

Why was the data set created?

The purpose of this polygon feature class is to identify the spatial extent and provenance of the source data used to create the continuous elevation surface. In addition the shapefile will also provide an inventory of the most recent elevation and bathymetry datasets within the Massachusetts coastal zone and offshore water and identify areas of the offshore waters that are only covered by historical lead-line soundings and should be updated by using new survey methods.

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: Jun-2016 (process 1 of 6)
    PROCESS STEP 1: CREATE EMPTY POLYGON FEATURE CLASS TO STORE THE OUTLINES OF ALL THE SOURCE DATA.
    Create an empty polygon feature class within a file geodatabase using the context menu in ArcCatalog (v. 10.3.1). Projection is set to UTM Zone 19 NAD 83. Add the following fields to the new feature class using the "add field" menu in the attribute table view: Source, SurvYear, PubLink, SourceType. All processing steps were completed by Brian Andrews. Person who carried out this activity:
    Brian Andrews
    U.S. Geological Survey
    Geographer
    384 Woods Hole Rd
    Woods Hole, MA
    USA

    508-548-8700 x2348 (voice)
    508-457-2310 (FAX)
    bandrews@usgs.gov
    Data sources produced in this process:
    • BuzzBay_Source (feature class)
    Date: Jul-2016 (process 2 of 6)
    PROCESS STEP 2: CREATE POLYGON BOUNDARY FILES FOR ALL LiDAR DATA.
    An 8-bit integer raster was created for each source LiDAR GeoTIFF listed in "Step 2" of the BuzzBay_10m.tif metadata using the grid query "Value less than 1000." The resulting integer raster was converted to polygon using the Raster to Polygon tool in ArcGIS (v. 10.3.1). Data sources produced in this process:
    • "SurveyName"_Mask
    Date: Jul-2016 (process 3 of 6)
    PROCESS STEP 3: CREATE BOUNDARY FILES FOR SWATH AND MULITBEAM DATA.
    An 8-bit integer raster was created for each source swath bathymetry grid listed in "Step 3 and 4" of the BuzzBay_10m.tif metadata using the grid query "Value less than 0." The resulting integer raster was converted to polygon using the Raster to Polygon tool in ArcGIS (v. 10.3.1) Data sources produced in this process:
    • "SurveyName"_Mask
    Date: Jul-2016 (process 4 of 6)
    PROCESS STEP 4: CREATE BOUNDARY FILES FOR ALL HISTORICAL NOS SOUNDING DATA.
    Create an empty polygon feature class for each of the historical NOS surveys using the context menu in ArcCatalog (v. 10.3.1). Projection is set to UTM Zone 19, NAD 83 (2011). Edit each of the polygons and digitize a boundary that encompasses all the input soundings. Data sources produced in this process:
    • "SurveyName"_Mask
    Date: Jul-2016 (process 5 of 6)
    PROCESS STEP 5: CLIP AND MERGE THE SOURCE POLYGONS INTO ONE FEATURE CLASS.
    This process was completed in three basic steps based on a data hierarchy using both qualitative and quantitative comparison between datasets in any areas of overlap. Starting with the LiDAR data, the individual polygons for each of the LiDAR surveys were compared for areas of overlap. In areas of overlap the newest LiDAR data with highest quality was generally used to clip (remove) overlapping older data used to create the terrain model. Qualitative criteria for determining which data to keep in areas of overlap included data density, data collection date, and data quality (are survey line artefacts visible). For example, along the south shore of Cape Cod, overlap exists between the 2007 and 2010 Army Corps of Engineers surveys. The full extent of the 2010 survey was used to clip (remove), the areas from the 2007 polygon because the 2010 data were more recent. The resulting clipped polygons were used later to extract the desired data for export as multipoint feature classes into the feature dataset used to create the terrain model. The vertical difference between overlapping raster data (LiDAR, swath, or multibeam) was used as a quantitative criteria for determining which data to retain in areas of overlap. Once these comparisons were conducted the polygons were clipped, then appended to the "MassBay_Source" feature class created in Step 1 above.
    Second, the polygons for swath and multibeam created in Step 3 above were clipped and appended to the "BuzzBay_Source" feature class in a similar manner as the LiDAR polygons. Polygon masks of newer multibeam data were used to clip older survey data in the areas of overlap. The final polygons representing swath and multibeam data were then used later to extract the desired depth data for export as a multipoint feature class to create the terrain model. Each source survey was exported as a separate multipoint, or simple point, feature class to facilitate data management.
    Finally, the polygons for each of the historical NOS surveys from Step 4 above were compared in areas of overlap with newer multibeam or LiDAR data and clipped to remove older historical sounding data. During the clip process, an additional buffer of 50 to 100 meters was applied using the "Buffer Distance" in the ArcGIS Clip Tool under the Edit Menu. This 50-100 meter gap created a smoother transition during the gridding process between high resolution data (LiDAR and multibeam) and low resolution data (historical NOS soundings). These edited polygons were then used to extract the desired sounding data for export as point feature class into the Terrain Model feature data set. The final polygons for each survey were appended to the "BuzzBay_Source" feature class. Data sources used in this process:
    • "SurveyName"_Mask
    Data sources produced in this process:
    • BuzzBay_Source
    Date: Jul-2016 (process 6 of 6)
    PROCESS STEP 6: EXPORT FEATURE CLASS TO SHAPEFILE:
    Finally, exported the BuzzBay_Source feature class into a Esri Shapefile using the context menu in ArcCatalog (v. 10.3.1). The projection of the output shapefile was set to Geographic NAD 83 during the export process. Data sources used in this process:
    • BuzzBay_Source feature class
    Data sources produced in this process:
    • BuzzBay_Source.shp
  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?
    No formal attribute accuracy tests were conducted.
  2. How accurate are the geographic locations?
    This polygon shapefile was generated by a combination of digitizing around actual sounding data, and converting rasters to polygons. Each feature in the shapefile encompasses the extent of each input dataset. The horizontal accuracy is dependant on the accuracy of the input dataset, and the scale used to digitize/edit the polygon features.
  3. How accurate are the heights or depths?
  4. Where are the gaps in the data? What is missing?
    The individual polygons only delineate the extent of data used to compile the terrain model and may not include all the data collected during the individual survey. Gaps exist between adjacent polygons.
  5. How consistent are the relationships among the observations, including topology?
    Polygon boundaries were created to outline the spatial extents of each input data source for the terrain model. The boundaries for the LiDAR and multibeam data were created by converting the boundary of the raster data to a polygon. The boundaries for the historical NOS sounding data were created by digitizing a boundary polygon around the extent for each of the datasets such that adjacent polygons do not overlap. The perimeter boundary of all four polygon datasets published in this data release were designed to overlap in order to create a seamless surface if the resulting GeoTIFFs are mosaicked together. General guidelines were established for the selection of the source elevation data, but for such a large area and complicated series of possible input datasets, the same source dataset may not have been chosen – therefore areas of overlap of the four individual datasets (BuzzBay_Source, CapeCodBay_Source , MassBay_Source, and Ntk_VS_Source) may not indicate the same source dataset.

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 (USGS) as the source of this information. Users are advised to read the data set's metadata thoroughly to understand appropriate use and data limitations.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey-ScienceBase
    Denver Federal Center, Building 810, Mail Stop 302
    Denver, CO
    USA

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? BuzzBay_Source.zip: file contains the polygon feature class (BuzzBay_Source.shp), BuzzBay_Source.jpg browse graphic, and the associated FGDC CSDGM metadata in XML, HTML, FAQ, and text formats.
  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?
    To utilize this data, the user must have software capable of reading an Esri shapefile.

Who wrote the metadata?

Dates:
Last modified: 05-Jan-2018
Metadata author:
Brian Andrews
U.S. Geological Survey, Northeast Region
Geographer
384 Woods Hole Road
Woods Hole, MA

508-548-8700 ext. 2348 (voice)
bandrews@usgs.gov
Metadata standard:
FGDC Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/whcmsc/data_release/DR_F72806T7/BuzzBay_SourceMeta.faq.html>
Generated by mp version 2.9.49 on Mon Sep 10 17:44:51 2018