High-resolution bathymetry data collected in 2005 in Skagit Bay, Washington

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Frequently anticipated questions:

What does this data set describe?

Title:
High-resolution bathymetry data collected in 2005 in Skagit Bay, Washington
Abstract:
These metadata describe the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) 2005 bathymetry data collected in Skagit Bay Washington that is provided as a 1-m resolution TIFF image, as well as a 1-m resolution shaded-relief TIFF image. In 2004, 2005, 2007, and 2010 the U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC) collected bathymetry and acoustic backscatter data in Skagit Bay, Washington using an interferometric bathymetric sidescan sonar system mounded to the USGS R/V Parke Snavely and the USGS R/V Karluk. The research was conducted in coordination with the Swinomish Indian Tribal Community, Skagit River System Cooperative, Skagit Watershed Council, Puget Sound Nearshore Ecosystem Restoration Project, and U.S. Army Corps of Engineers to characterize estuarine habitats and processes, including the sediment budget of the Skagit River and the influence of river-delta channelization on sediment transport. Information quantifying the distribution of habitats and extent that sediment transport influences habitats and the morphology of the delta is useful for planning for salmon recovery, agricultural resilience, flood risk protection, and coastal change associated with sea-level rise.
Supplemental_Information:
Additional information about the field activities from which these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=K104PS https://cmgds.marine.usgs.gov/fan_info.php?fan=K205PS https://cmgds.marine.usgs.gov/fan_info.php?fan=K107PS https://cmgds.marine.usgs.gov/fan_info.php?fan=S410PS
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
  1. How might this data set be cited?
    Grossman, Eric E., Dartnell, Peter, and Finlayson, David P., 2018, High-resolution bathymetry data collected in 2005 in Skagit Bay, Washington: data release DOI:10.5066/F7JM27VN, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Grossman, Eric E., Dartnell, Peter, and Finlayson, David P., 2018, High-resolution bathymetry and acoustic-backscatter data collected in 2004, 2005, 2007, and 2010 in Skagit Bay, Washington: data release DOI:10.5066/F7JM27VN, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, CA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.568
    East_Bounding_Coordinate: -122.448
    North_Bounding_Coordinate: 48.396
    South_Bounding_Coordinate: 48.276
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/59c16044e4b091459a5faec5?name=SkagitBay_2005_QV.jpg&allowOpen=true (JPEG)
    quick view image of 2005 Skagit Bay bathymetry data
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2005
    Ending_Date: 2005
    Currentness_Reference:
    ground condition at time data were collected.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: TIFF
  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 15941 x 9184 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: 10
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.9996
      Longitude_of_Central_Meridian: -123.00000
      Latitude_of_Projection_Origin: 0.00000
      False_Easting: 500000.0
      False_Northing: 0.00
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 1.0
      Ordinates (y-coordinates) are specified to the nearest 1.0
      Planar coordinates are specified in Meters
      The horizontal datum used is NAD83.
      The ellipsoid used is GRS80.
      The semi-major axis of the ellipsoid used is 6378137.00.
      The flattening of the ellipsoid used is 1/298.257223563.
      Vertical_Coordinate_System_Definition:
      Altitude_System_Definition:
      Altitude_Datum_Name: North American Datum 1983
      Altitude_Resolution: 0.1
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method:
      Explicit elevation coordinate included with horizontal coordinates
  7. How does the data set describe geographic features?
    value
    depth in meters relative to NAVD88 (Source: Producer defined)
    Entity_and_Attribute_Overview:
    The complete 1-m resolution 2005 Skagit Bay bathymetry grid was originally archived as a TIFF image with the following attributes. 
    Cell size = 1.0
Number of rows = 15941
Number of columns = 9184

Data type = floating point

Boundary
Xmin = 531268
Xmax = 540452
Ymin = 5344416
Ymax = 5360357

Statistics
Minimum value = -106.73
Maximum value = 1.86
Mean = -19.77
Standard deviation = 17.29

Coordinate system description
Projection  UTM
Zone  10
Datum  NAD83
Vertical Reference NAVD88
Units  meter
    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)
    • Eric E. Grossman
    • Peter Dartnell
    • David P. Finlayson
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    Peter Dartnell
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Physical Scientist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7415 (voice)
    831-427-4748 (FAX)
    pdartnell@usgs.gov

Why was the data set created?

These data are intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to identify bathymetric features. These data are not intended to be used for navigation.

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: 2017 (process 1 of 2)
    In 2005 the USGS, PCMSC mapped a portion of Skagit Bay within Puget Sound, Washington. A 234-kHz interferometric bathymetric sidescan sonar system was pole-mounted to the USGS, PCMSC R/V Karluk. In 2017 the USGS, PCMSC downloaded the 2005 survey line files from the USGS archives. The survey line files were imported into Caris HIPS and SIPS software (version 9). Soundings were cleaned of obvious incorrect data and manual sound veolocity corrections were applied on some lines. The data were then gridded into a 1-m resolution base surface using the swath angle method. The base surface was exported as a TIFF file in UTM-10 coordinates referenced to the WGS84 ellipsoid. The TIFF file was imported into a Geographic Information System (ESRI, ArcMap) and converted to a grid, then converted to an ASCII XYZ file using Fledermaus software. The XYZ file coordinates and depths were transformed to NAD83 coordinates relative to NAVD88 depths using V-Datum software (version 3.7). The new XYZ file was gridded into a 1-m surface using Fledermaus software, exported as an ASCIIRaster file, imported into a GIS and then export as a TIFF file in UTM, zone 10 NAD83 coordinates relative to NAVD88. Also, a shaded relief bathymetry grid was generated from the bathymetry data using the ESRI, ArcMap 'hillshade' tool. The grid was then exported as a TIFF file in UTM zone 10, NAD-83 coordinates. The image does not contain depth/elevation information.
    Date: 19-Oct-2020 (process 2 of 2)
    Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed. 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?

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

  1. How well have the observations been checked?
    Not applicable for raster data.
  2. How accurate are the geographic locations?
    Estimated to be no less than 1 m, owing to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.
  3. How accurate are the heights or depths?
    Estimated to be no less than 0.5% water depth, owing to water depth and total propagated uncertainties of the mapping systems, which include sonar system, position and motion compensation system, and navigation, as well as data processing that includes sounding cleaning, gridding, and datum transformations.
  4. Where are the gaps in the data? What is missing?
    Dataset is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
  5. How consistent are the relationships among the observations, including topology?
    No formal logical accuracy tests were conducted.

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:
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originators of the dataset and in products derived from these data. This information is not intended for navigation purposes.
  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

    1-888-275-8747 (voice)
    sciencebase@usgs.gov
  2. What's the catalog number I need to order this data set? These data are available in TIFF format (skagitbay_2005_bathmetry_1m_utm10_nad83_navd88.tif) contained in a single zip file (skagitbay_2005_bathymetry_1m_utm10_nad83_navd88.zip), which includes a tif world file (.tfw) and CSDGM FGDC-compliant metadata. A shaded-relief version (skagitbay_2005_shadedrelief_1m_utm10_nad83.tif) is contained in a second zip file (skagitbay_2005_shadedrelief_1m_utm10_nad83.zip), which also includes a tif world file (.tfw) and CSDGM FGDC-compliant metadata.
  3. What legal disclaimers am I supposed to read?
    Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by 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.
  4. How can I download or order the data?
  5. What hardware or software do I need in order to use the data set?
    The downloadable data file has been compressed with the "zip" command and can be unzipped with Winzip (or other tool) on Windows systems. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing a TIFF file.

Who wrote the metadata?

Dates:
Last modified: 19-Oct-2020
Metadata author:
Peter Dartnell
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
2885 Mission Street
Santa Cruz, CA
United States of America

831-460-7415 (voice)
pdartnell@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)
This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/DataReleases/ScienceBase/DR_F7JM27VN/skagitbay_2005_bathymetry_1m_metadata.faq.html>
Generated by mp version 2.9.50 on Tue Sep 21 18:17:19 2021