Backscatter [8101]--Offshore of Monterey, California

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What does this data set describe?

Title: Backscatter [8101]--Offshore of Monterey, California
Abstract:
This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Monterey map area, California. Backscatter data are provided as separate grids depending on resolution. This metadata file refers to the data included in "Backscatter_8101_OffshoreMonterey.zip," which is accessible from https://doi.org/10.5066/F70Z71C8. These data accompany the pamphlet and map sheets of Johnson, S.Y., Dartnell, P., Hartwell, S.R., Cochrane, G.R., Golden, N.E., Watt, J.T., Davenport, C.W., Kvitek, R.G., Erdey, M.D., Krigsman, L.M., Sliter, R.W., and Maier, K.L. (S.Y. Johnson and S.A. Cochran, eds.), 2016, California State Waters Map Series—Offshore of Monterey, California: U.S. Geological Survey Open-File Report 2016–1110, pamphlet 44 p., 10 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20161110.
The acoustic-backscatter map of the Offshore of Monterey map area in central California was generated from backscatter data collected by California State University, Monterey Bay (CSUMB) and by Monterey Bay Aquarium Research Institute (MBARI). Mapping was completed between 1998 and 2012 using a combination of multibeam echosounders including 200-kHz/400-kHz Reson 7125, 100-kHz Reson 7111, 240 kHz Reson 8101, and 30-kHz Simrad EM-300 as well as 234-kHz and 468-kHz SWATHplus bathymetric sidescan-sonar system. Within the final imagery, brighter tones indicate higher backscatter intensity, and darker tones indicate lower backscatter intensity. The intensity represents a complex interaction between the acoustic pulse and the seafloor, as well as characteristics within the shallow subsurface, providing a general indication of seafloor texture and composition. Backscatter intensity depends on the acoustic source level; the frequency used to image the seafloor; the grazing angle; the composition and character of the seafloor, including grain size, water content, bulk density, and seafloor roughness; and some biological cover. Harder and rougher bottom types such as rocky outcrops or coarse sediment typically return stronger intensities (high backscatter, lighter tones), whereas softer bottom types such as fine sediment return weaker intensities (low backscatter, darker tones).
  1. How might this data set be cited?
    Dartnell, Peter, and Kvitek, Rikk G., 2016, Backscatter [8101]--Offshore of Monterey, California: Data Series DS 781, U.S. Geological Survey, Reston, VA.

    Online Links:

    This is part of the following larger work.

    Golden, Nadine E., 2015, California State Waters Map Series Data Catalog: Data Series DS 781, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.06
    East_Bounding_Coordinate: -121.78
    North_Bounding_Coordinate: 36.69
    South_Bounding_Coordinate: 36.53
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/56cf5fc5e4b015c306ed183c?name=Backscatter_8101_OffshoreMonterey.jpg&allowOpen=true (JPEG)
    Acoustic backscatter imagery offshore of Monterey.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2000
    Ending_Date: 2006
    Currentness_Reference:
    ground condition
  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 4462 x 2651 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 2.0
      Ordinates (y-coordinates) are specified to the nearest 2.0
      Planar coordinates are specified in Meters
      The horizontal datum used is WGS84.
      The ellipsoid used is WGS84.
      The semi-major axis of the ellipsoid used is 6378137.00.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    Value
    Backscatter [CSUMB 8101] intensity value (Source: ESRI)
    VALUE
    Backscatter intensity values (Source: ESRI)
    Range of values
    Minimum:1
    Maximum:255
    Units:Floating point values representing intensity
    Entity_and_Attribute_Overview:
    The Reson 8101 acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:
    Cell size = 2.0
    Number of rows = 8841
    Number of columns = 12433
    
    Data type = floating point
    
    Boundary
    Xmin = 583711
    Xmax = 608575
    Ymin = 4043542
    Ymax = 4061223
    
    Statistics
    Minimum value = 1
    Maximum value = 255
    Mean = 157.51
    Standard deviation = 53.04
    
    Coordinate system description
    Projection  UTM
    Zone  10
    Datum  WGS84
    Units  meter
    
    Entity_and_Attribute_Detail_Citation: none

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Peter Dartnell
    • Rikk G. Kvitek
  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?

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.

How was the data set created?

  1. From what previous works were the data drawn?
    Can Row SSS (source 1 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, CanRowMosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (1-meter resolution).
    Hope Deep Reef SSS (source 2 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, HopDeepReefmosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (1-meter resolution).
    Hope to Lovers Pt SSS (source 3 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, Hoplovptmosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
    Lovers Pt SSS (source 4 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, LovPtPtPnsmosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
    Monastery Mosaic SSS (source 5 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, Monasterymosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
    Peninsula Mosaic SSS (source 6 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, PinnNESWMosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
    Cypress Pt SSS (source 7 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, PtJoeCypressPtMosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
    Pt Pinos SSS (source 8 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, Ptpinosptjoemosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
    So Cypress Pt SSS (source 9 of 9)
    Seafloor Mapping Lab, California State University Monterey Bay, 20061231, SoCypressPtMosaic.tif.

    Online Links:

    Type_of_Source_Media: digital file of gridded sidescan
    Source_Contribution: Gridded sidescan sonar data (0.2-meter resolution).
  2. How were the data generated, processed, and modified?
    Date: 2006 (process 1 of 7)
    During the CSUMB mapping missions, an Applanix POS MV (Position and Orientation System for Marine Vessels) or a Teledyne TSS HDMS (Hydrographic Data Maintenance System) was used to provide position and attitude data during data collection, and they also accounted for vessel motion such as heave, pitch, and roll with navigational input from Trimble 4700 GPS or Cnav®-enabled NAVCON 2050 GPS receivers. Kinetic GPS (KGPS) altitude data were used to account for tide cycle fluctuations, and sound-velocity profiles were collected with an Applied Microsystems (AM) SVPlus sound velocimeter. Soundings were corrected for vessel motion using the Applanix POS MV or Teledyne TSS HDMS data, for variations in water-column sound velocity using the AM SVPlus data, and for variations in water height (tides) using vertical-position data from postprocessed GPS data. The Reson backscatter data were postprocessed using a variety of methods including Geocoder software, Isis Sonar and Delph Map software, and TNT Mips GIS software. For the data postprocessed using Geocoder, the backscatter intensities were radiometrically corrected (including despeckling and angle-varying gain adjustments), and the position of each acoustic sample was geometrically corrected for slant range on a line-by-line basis. After the lines were corrected, they were mosaicked into 1- or 2-m-resolution images. Overlap between parallel lines was resolved using a priority table whose values were based on the distance of each sample from the ship track, with samples that were closest to and furthest from the ship track being given the lowest priority. An anti-aliasing algorithm was also applied. The mosaics were then exported as georeferenced TIFF images, imported into a Geographic Information System (GIS), and converted to GRIDs at 1-m resolution. For the backscatter data postprocessed using the Isis, Delph Map, and TNT Mips method, individual tracklines were replayed and bottom tracking of the sonar was supervised to aid in proper slant-range correction. Line files were snipped to remove portions with poor imagery from the beginning and (or) end of the trackline. Tracklines were then corrected for slant-range and layback, and the position data for each line was smoothed using a speed filter. Each line was then gridded, georeferenced, and exported from Isis Sonar/Delph Map in GeoTIFF format. Individual trackline TIFF images were imported into TNT Mips GIS software and areas of poor image quality were extracted and removed. Individual tracklines were then overlaid to produce a mosaic image. Geotiffs were exported from TNT Mips, imported into a GIS and converted to GRIDs at 2-m spatial resolution (California State University, Monterey Bay, Seafloor Mapping Lab, 2015) Person who carried out this activity:
    Carrie Bretz
    Seafloor Mapping Lab, California State University Monterey Bay
    Projects Manager, GIS & Metadata Supervisor
    100 Campus Center, Bldg 13
    Seaside, CA
    USA

    831.582.4197 (voice)
    carrie_bretz@csumb.edu
    Date: 2015 (process 2 of 7)
    California Seafloor Mapping Project 1- or 2-m resolution backscatter imagery within the Offshore of Monterey map area were downloaded from California State University, Monterey Bay, Seafloor Mapping Lab (http://seafloor.csumb.edu/SFMLwebDATA.htm) and converted to grids. Backscatter grids from similar mapping systems were merged together in a GIS and clipped to the boundary of the map area. Grids from different mapping systems were not merged together due to different mapping frequencies and processing techniques. Grids were downsampled to 2-m resolution and projected horizontally to WGS-84 using ESRI ArcTools. Person who carried out this activity:
    Pete Dartnell
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Physical Scientist
    2885 Mission St.
    Santa Cruz, CA
    USA

    (831) 460-7415 (voice)
    pdartnell@usgs.gov
    Date: 05-Oct-2017 (process 3 of 7)
    Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Alan O. Allwardt
    Contractor -- Information Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7551 (voice)
    831-427-4748 (FAX)
    aallwardt@usgs.gov
    Date: 26-Apr-2018 (process 4 of 7)
    Added keywords from Coastal and Marine Ecological Classification Standard (CMECS) to metadata. Person who carried out this activity:
    U.S. Geological Survey
    Attn: Alan O. Allwardt
    Contractor -- Information Specialist
    2885 Mission Street
    Santa Cruz, CA

    831-460-7551 (voice)
    831-427-4748 (FAX)
    aallwardt@usgs.gov
    Date: 19-Oct-2020 (process 5 of 7)
    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: 14-Oct-2021 (process 6 of 7)
    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
    Date: 20-May-2022 (process 7 of 7)
    Edits were made to bring the metadata up to current PCMSC standards including standardizing authors' names, adding a doi# link, correcting typos, refining keywords, and using current access and distribution liability statements. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. No data were changed. The metadata available from a harvester may supersede metadata bundled within a download file. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version. 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?
    Johnson, S.Y., Dartnell, P., Hartwell, S.R., Cochrane, G.R., Golden, N.E., Watt, J.T., Davenport, C.W., Kvitek, R.G., Erdey, M.D., Krisgman, L.M., Sliter, R.W., and Maier, K.L., 2016, California State Waters Map Series--Offshore of Monterey, California: Open-File Report 2016-1110, 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?
    Not applicable for raster data.
  2. How accurate are the geographic locations?
    Estimated to be no less than 2 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?
    Not applicable to acoustic-backscatter imagery.
  4. Where are the gaps in the data? What is missing?
    Complete
  5. How consistent are the relationships among the observations, including topology?
    Unspecified

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. Acknowledge the U.S. Geological Survey, California State University, Monterey Bay, Seafloor Mapping Lab, and Monterey Bay Aquarium Research Institute in products derived from these data. Share data products developed using these data with the U.S. Geological Survey. This information is not intended for navigational purposes. Read and fully comprehend the metadata prior to data use. Uses of these data should not violate the spatial resolution of the data. Where these data are used in combination with other data of different resolution, the resolution of the combined output will be limited by the lowest resolution of all the data. This database has been approved for release and publication by the Director of the USGS. Although this database has been subjected to rigorous review and is substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although this Federal Geographic Data Committee-compliant metadata file is intended to document these data in nonproprietary form, as well as in ArcInfo format, this metadata file may include some ArcInfo-specific terminology.
  1. Who distributes the data set? (Distributor 1 of 1)
    U.S. Geological Survey
    345 Middlefield Rd
    Menlo Park, CA
    USA

    (650) 329-4309 (voice)
  2. What's the catalog number I need to order this data set?
  3. What legal disclaimers am I supposed to read?
    These databases, identified as acoustic-backscatter maps of the Offshore of Monterey map area, California have been approved for release and publication by the U.S. Geological Survey (USGS). Although these databases have been subjected to rigorous review and are substantially complete, the USGS reserves the right to revise the data pursuant to further analysis and review. Furthermore, it is released on condition that neither the USGS nor the United States Government may be held liable for any damages resulting from its authorized or unauthorized use. Although these data have been processed successfully on a computer system at 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. The USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. These data are not intended for navigational use.
  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 an Esri ArcMap TIFF. Users should download the ArcGIS Project File, OffshoreMontereyGIS.mxd.zip, a compressed (with the "zip" command) version of the ArcMap document (.mxd) that has all the data layers loaded in the table of contents for "Offshore of Monterey map area" and has all the data symbolized as on the data release map sheets. Download and save this ArcGIS project file, including all data layers, to the directory the user has created for this GIS.

Who wrote the metadata?

Dates:
Last modified: 20-May-2022
Metadata author:
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
Metadata standard:
Content Standard for Digital Geospatial Metadata (FGDC-STD-001-1998)

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