Acoustic-backscatter data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018

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Frequently anticipated questions:

What does this data set describe?

Title:
Acoustic-backscatter data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018
Abstract:
This part of the data release contains high-resolution acoustic-backscatter data collected by the U.S. Geological Survey (USGS) Pacific Coastal and Marine Science Center at three study locations in the Sacramento-San Joaquin Delta, California. Data were collected in Lindsey Slough in April 2017, Middle River in March 2018, and Mokelumne River in March 2018, using an interferometric bathymetric sidescan sonar systems mounted to the USGS R/V Parke Snavely. Data are provided in 1-m resolution GeoTIFF formats. These data were collected as part of a study of the effects of invasive aquatic vegetation on sediment transport in the Sacramento-San Joaquin Delta.
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=2017-616-FA https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-609-FA 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?
    Dartnell, Peter, Lacy, Jessica R., and Stevens, Andrew, 20200518, Acoustic-backscatter data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018: data release doi:10.5066/P9112AIP, U.S. Geological Survey, Pacific Coastal and Marine Science Center Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Lacy, Jessica R., Joanne C. T. Ferreira, Dailey, Evan T., Dartnell, Peter, Drexler, Judith Z., Allen, Rachel M., and Stevens, Andrew, 2020, Sediment transport and aquatic vegetation data from three locations in the Sacramento-San Joaquin Delta, California, 2017 to 2018: data release doi:10.5066/P9112AIP, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -121.7089
    East_Bounding_Coordinate: -121.5289
    North_Bounding_Coordinate: 38.251
    South_Bounding_Coordinate: 37.94614
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/Acoustic_backscatter_data_Sacramento-San_Joaquin_Delta_2017-2018_acoustic_data_collection_sites.png&allowOpen=true (PNG)
    Image of 2017-2018 acoustic-backscatter data collection sites
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 04-Apr-2017
    Ending_Date: 28-Mar-2018
    Currentness_Reference:
    ground condition at time data were collected.
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: GeoTIFF
  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, 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: 0.999600
      Longitude_of_Central_Meridian: -123.000000
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000
      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 1.000000
      Ordinates (y-coordinates) are specified to the nearest 1.000000
      Planar coordinates are specified in Meters
      The horizontal datum used is North American Datum 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    value
    backscatter intensity as a digital number (Source: Producer defined)
    backscatter intensity
    backscatter intensity as a digital number (Source: Producer defined)
    Range of values
    Minimum:0
    Maximum:65535
    Units:backscatter intensity as a digital number
    Resolution:1

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Peter Dartnell
    • Jessica R. Lacy
    • Andrew Stevens
  2. Who also contributed to the data set?
  3. To whom should users address questions about the data?
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Attn: PCMSC Science Data Coordinator
    2885 Mission Street
    Santa Cruz, CA
    US

    831-427-4747 (voice)
    pcmsc_data@usgs.gov

Why was the data set created?

The acoustic-backscatter survey was conducted as part of a cooperative project with the USGS California Water Science Center and the California Department of Fish and Wildlife to provide critical data about the impact of Invasive Aquatic Vegetation (IAV) on fish habitat and the health of marshes to agencies that manage and control IAV in the Delta. The acoustic-backscatter data were used to determine the edge of vegetation. These data are intended for science researchers, students, policy makers, and the general public. The 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 4)
    In 2017 the USGS, PCMSC mapped in Lindsey Slough, California. An interferometric bathymetric sidescan sonar system was mounted to the USGS, PCMSC R/V Parke Snavely. Post-processed Applanix POS-MV attitude data (SBET) were merged with each original survey line file to create new post-processed survey line files. The post-processed line files were imported into SonarWiz software (version 6) for backscatter processing. Processed backscatter grids were exported as Imagine images in UTM zone 10 WGS84 coordinates. The images were imported into ArcGIS and projected to UTM zone 10, NAD83 coordinates using the ArcTools project raster function. The backscatter images were then exported as GeoTIFF images in UTM zone 10, NAD83 coordinates.
    Date: 2020 (process 2 of 4)
    In 2018 the USGS, PCMSC mapped in the Mokelumne and Middle Rivers, California. An interferometric bathymetric sidescan sonar system was mounted to the USGS, PCMSC R/V Parke Snavely. Post-processed Applanix POS-MV attitude data (SBET) were merged with each original survey line file to create new post-processed survey line files. The post-processed line files were imported into SonarWiz software (version 6) for backscatter processing. Processed backscatter grids were exported as Imagine images in UTM zone 10 WGS84 coordinates. The images were imported into ArcGIS and projected to UTM zone 10, NAD83 coordinates using the ArcTools project raster function. The backscatter images were then exported as GeoTIFF images in UTM zone 10, NAD83 coordinates.
    Date: 19-Oct-2020 (process 3 of 4)
    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
    Date: 13-Oct-2021 (process 4 of 4)
    Performed minor edits to the metadata to correct typos. No data were changed. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Susan A. Cochran
    Geologist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7545 (voice)
    scochran@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?
    The Applanix POS-MV post-processed horizontal positional accuracy is about 0.1 m with roll and pitch accuracies of about 0.02 degrees (https://www.applanix.com/downloads/products/specs/posmv/POS-MV-WaveMaster-II.pdf). The SWATHPlus sonar system (234 kHz) has an across track resolution of about 5 cm (http://www.bathyswath.com/sites/default/files/documents/ETD_2002_Bathyswath%20information_EN.pdf). Accuracies of final products may be lower due to 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?
    Not Applicable to acoustic-backscatter data
  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
    USA

    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 zipped GeoTIFF format, including a tif world file (.tfw) for each study area, accompanied by CSDGM FGDC-compliant metadata and a browse image.
  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 archive utilites. To utilize these data, the user must have software capable of uncompressing the WinZip file and importing and viewing a GeoTIFF file.

Who wrote the metadata?

Dates:
Last modified: 13-Oct-2021
Metadata author:
PCMSC Science Data Coordinator
U.S. Geological Survey, Pacific Coastal and Marine Science Center
2885 Mission Street
Santa Cruz, CA
United States

831-427-4747 (voice)
pcmsc_data@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_P9112AIP/Acoustic_backscatter_data_Sacramento-San_Joaquin_Delta_2017-2018.faq.html>
Generated by mp version 2.9.50 on Thu Oct 14 14:47:21 2021