Multibeam acoustic-backscatter data collected offshore of south-central California in support of the Bureau of Ocean Energy Management Cal DIG I offshore alternative energy project

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Frequently anticipated questions:


What does this data set describe?

Title:
Multibeam acoustic-backscatter data collected offshore of south-central California in support of the Bureau of Ocean Energy Management Cal DIG I offshore alternative energy project
Abstract:
Multibeam acoustic-backscatter data were collected offshore of Morro Bay, California, from 2016 to 2019. The data were collected during five separate multi-agency surveys for the U.S. Geological Survey (USGS)/Bureau of Ocean Energy Management (BOEM) California Deepwater Investigations and Groundtruthing I (Cal DIG I) project, under a collaboration with the National Oceanic and Atmospheric Administration (NOAA), using Simrad 700 series hull-mounted multibeam echosounders. Data in 2017 and 2018 were acquired by the NOAA Hydrographic Vessel Rainier (surveys H1309, H13151, and H13152). The 2018 data acquired by the Ranier were collected during USGS field activity 2018-641-FA. Additional data were collected in 2019 by the NOAA Hydrographic Survey Vessel Fairweather (survey W00479). Data from the Scripps Institution of Oceanography R/V Sally Ride collected in 2016 (survey SR1604) were used to fill in a small gap in the NOAA data. The acoustic-backscatter data from the five surveys were combined into a single raster and are provided as a 10-meter resolution GeoTIFF.
Supplemental_Information:
Additional information about the USGS field activity from which some of these data were derived is available online at:
https://cmgds.marine.usgs.gov/fan_info.php?fan=2018-641-FA
These data were collected for the U.S. Geological Survey (USGS)/Bureau of Ocean Energy Management (BOEM) California Deepwater Investigations and Groundtruthing I (Cal DIG I) project (Interagency Agreement M17PG00021).
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?
    Cochrane, Guy R., and Dartnell, Peter, 20220108, Multibeam acoustic-backscatter data collected offshore of south-central California in support of the Bureau of Ocean Energy Management Cal DIG I offshore alternative energy project: data release DOI:10.5066/P9QQZ27U, U.S. Geological Survey, Pacific Coastal and Marine Science Center, Santa Cruz, California.

    Online Links:

    This is part of the following larger work.

    Cochrane, Guy R., Kuhnz, Linda A., Dartnell, Peter, Gilbane, Lisa, and Walton, Maureen A., 2022, Multibeam echosounder, video observation, and derived benthic habitat data offshore of south-central California in support of the Bureau of Ocean Energy Management Cal DIG I, offshore alternative energy project: data release DOI:10.5066/P9QQZ27U, 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: -121.996378
    East_Bounding_Coordinate: -120.792132
    North_Bounding_Coordinate: 35.901422
    South_Bounding_Coordinate: 34.516318
  3. What does it look like?
    Cal_DIG_1_Backscatter_10m.jpeg (JPEG)
    Quick view of Cal DIG I backscatter intensity data
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2016
    Ending_Date: 2019
    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 15186 x 11210 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 10.0
      Ordinates (y-coordinates) are specified to the nearest 10.0
      Planar coordinates are specified in Meters
      The horizontal datum used is NAD83.
      The ellipsoid used is NAD83.
      The semi-major axis of the ellipsoid used is 6378137.00.
      The flattening of the ellipsoid used is 1/298.257222101.
  7. How does the data set describe geographic features?
    value
    backscatter intensity as a digital value (Source: Producer defined)
    Entity_and_Attribute_Overview:
    The complete 10-m resolution CalDIG I acoustic-backscatter grid is a GeoTIFF image with the following attributes.
    Cell size = 10.0
    Number of rows = 15186
    Number of columns = 11210
    
    Data type = floating point
    
    Boundary
    Xmin = 590568
    Xmax = 702668
    Ymin = 3821620
    Ymax = 3973480
    
    Statistics
    Minimum value = 0
    Maximum value = 255
    Mean = 123.1648
    Standard deviation = 21.4859
    Coordinate system description
    Projection UTM
    Zone 10
    Datum NAD 83
    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)
    • Guy R. Cochrane
    • Peter Dartnell
  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

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

Why was the data set created?

The surveys were conducted to map surficial geology and benthic habitat as part of the USGS/BOEM Interagency Agreement M17PG0021 titled California Deepwater Investigations and Groundtruthing I (Cal DIG I). These data are intended to provide regional surficial geology and benthic habitat information in an area of interest for offshore wind energy development. These data are also intended for science researchers, students, policy makers, and the general public. These data can be used with geographic information systems or other software to help identify geomorphologic features and surficial lithology. 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: 2020 (process 1 of 1)
    Backscatter data collected in the Cal DIG I study area off Morro Bay were acquired with Simrad EM 700 series echosounders. The data were processed with Caris SIPS software into 10-meter resolution rasters. NOAA processed data from surveys H1309, H13151, and H13152. The USGS processed the data from SF1604 and W00479. The individual survey rasters were imported into an ArcGIS Geographic Information Systems (GIS). The brightness and contrast of some of the individual rasters were adjusted using ArcGIS reclassify to better match the adjacent images. All the individual images were then merged into one overall backscatter image. The image was exported as a GeoTIFF file in UTM zone 10, NAD83 coordinates.
  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 POS MV position and motion compensation system has a horizontal positional accuracy of about 0.5 m with DGPS corrections and roll and pitch accuracies of about 0.02 degrees (http://www.measutronics.com/wp-content/uploads/2011/01/posmv320_specifications.pdf). Accuracies of final products may be lower due 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?
    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 and the Alaska Department of Fish and Game 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 - CMGDS
    2885 Mission Street
    Santa Cruz, CA

    831-427-4747 (voice)
    pcmsc_data@usgs.gov
  2. What's the catalog number I need to order this data set? These data are available in GeoTIFF format, along with 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?
    • Availability in digital form:
      Data format: These data are available in GeoTIFF format, along with a tif world file (.tfw) and CSDGM FGDC-compliant metadata. in format GeoTIFF (version ArcMap (version 10.7.1)) Size: 239.9
      Network links: https://doi.org/10.5066/P9QQZ27U
    • Cost to order the data: None.

  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 GeoTIFF file.

Who wrote the metadata?

Dates:
Last modified: 08-Jan-2022
Metadata author:
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Attn: PCMSC Science Data Coordinator
2885 Mission Street
Santa Cruz, CA

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/CMGDS_DR_tool/DR_P9QQZ27U/Cal_DIG_I_Backscatter_10m_Metadata.faq.html>
Generated by mp version 2.9.50 on Tue Jan 11 18:23:53 2022