Contours--Offshore Santa Cruz, California

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What does this data set describe?

Title: Contours--Offshore Santa Cruz, California
Abstract:
This part of DS 781 presents data for the bathymetric contours for several seafloor maps of the Offshore Santa Cruz map area, California. The vector data file is included in "Contours_OffshoreSantaCruz.zip", which is accessible from http://dx.doi.org/10.5066/F7TM785G. 10-m interval contours of the Offshore Santa Cruz map area, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS). Mapping was completed in 2009 using a 234-kHz SWATHplus bathymetric sidescan-sonar system. The mapping mission collected bathymetry data from about the 10-m isobath to beyond the 3-nautical-mile limit of California’s State Waters. Bathymetric contours at 10-m intervals were generated from a modified 2-m bathymetric surface. The original surface was smoothed using the Focal Mean tool in ArcGIS and a circular neighborhood with a radius of 20 to 30 meters (depending on the area). The contours were generated from this smoothed surface using the ArcGIS Spatial Analyst Contour tool. The most continuous contour segments were preserved while smaller segments and isolated island polygons were excluded from the final output. The contours were then clipped to the boundary of the map area.
  1. How might this data set be cited?
    Erdey, Mercedes D., 2015, Contours--Offshore Santa Cruz, California:.

    This is part of the following larger work.

    Cochrane, Guy R., Dartnell, Peter, Johnson, Samuel Y., Erdey, Mercedes D., Golden, Nadine E., Greene, H. Gary, Dieter, Bryan E., Hartwell, Stephen R., Ritchie, Andrew C., Finlayson, David P., Endris, Charles A., Watt, Janet T., Davenport, Clifton W., Sliter, Ray W., Maier, Katie L., and Krigsman, Lisa M., 2015, California State Waters Map Series--Offshore of Santa Cruz Map Area, California: U.S. Geological Survey data set F7348HF0, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.20
    East_Bounding_Coordinate: -122.00
    North_Bounding_Coordinate: 37.00
    South_Bounding_Coordinate: 36.84
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/556767ece4b0d9246a9ec5bc?f=__disk__41%2Fb0%2Fff%2F41b0ffa73dc3951cbc545e7c324e3b004b58a69b&width=150&height=147 (JPEG)
    Contours derived from bathymetry of offshore Santa Cruz.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2009
    Ending_Date: 2009
    Currentness_Reference:
    ground condition
  5. What is the general form of this data set?
    Geospatial_Data_Presentation_Form: vector digital data
  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):
      • String (37)
    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 0.01
      Ordinates (y-coordinates) are specified to the nearest 0.01
      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 meters.
      The flattening of the ellipsoid used is 1/298.257223563.
  7. How does the data set describe geographic features?
    Contours_OffshoreSantaCruz.shp
    The shapefile attributes include FID - Internal Feature Number, SHAPE - feature geometry, ID - feature ID, and CONTOUR - contour depth value. The shapefile can be added to any ESRI ArcMap project. (Source: ESRI)
    FID
    Internal feature number. (Source: ESRI) Sequential unique whole numbers that are automatically generated.
    SHAPE
    Feature geometry (Source: ESRI) Polyline
    ID
    Unique identifier for each contour line. Value of 0 means the line segment has been generated during the smoothing process. (Source: ESRI)
    Range of values
    Minimum:214
    Maximum:371
    Units:Double
    CONTOUR
    Contours are lines that connect points of equal depth based on the bathymetry grid. The contour values indicate the depth value the line represents. This makes it easier to identifier features on the seafloor. Contour lines were generated at 10-m intervals, from -10 m to -90 m, then the contours were clipped to the boundary of the map area. Values are negative to indicate depth below sea level. (Source: USGS)
    Range of values
    Minimum:-90
    Maximum:-10
    Units:Integer values -10 to -90 representing depth intervals as described above

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Mercedes D. Erdey
  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
    400 Natural Bridges Dr.
    Santa Cruz, CA
    USA

    (831) 460-7415 (voice)
    (831) 427-4709 (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: 2009 (process 1 of 4)
    During the USGS mapping mission, GPS data with real-time-kinematic corrections were combined with measurements of vessel motion (heave, pitch, and roll) in a CodaOctopus F180 attitude-and-position system to produce a high-precision vessel-attitude packet. This packet was transmitted to the acquisition software in real time and combined with instantaneous sound-velocity measurements at the transducer head before each ping. The returned samples were projected to the seafloor using a ray-tracing algorithm that works with previously measured sound-velocity profiles. Statistical filters were applied to discriminate seafloor returns (soundings and backscatter intensity) from unintended targets in the water column. Finally, the soundings were converted into 2-m-resolution bathymetric-surface-model grid. Bathymetric contours at 10-m intervals were generated from a modified 2-m bathymetric surface. The original surface was smoothed using the Focal Mean tool in ArcGIS and a circular neighborhood with a radius of 20 to 30 meters (depending on the area). The contours were generated from this smoothed surface using the ArcGIS Spatial Analyst Contour tool. The most continuous contour segments were preserved while smaller segments and isolated island polygons were excluded from the final output. The contours were then clipped to the boundary of the map area. Person who carried out this activity:
    Peter Dartnell
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Physical Scientist
    400 Natural Bridges Dr.
    Santa Cruz, CA
    USA

    831-460-7415 (voice)
    pdartnell@usgs.gov
    Date: 05-Oct-2017 (process 2 of 4)
    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 3 of 4)
    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: 22-Jun-2018 (process 4 of 4)
    Corrected author spelling in Larger Work section Person who carried out this activity:
    Susan A Cochran
    U.S. Geological Survey, Pacific Coastal and Marine Science Center
    Geologist
    2885 Mission Street
    Santa Cruz, CA
    USA

    (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?
    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?
    Estimated to be no less than 20 cm, 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?
    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 and California State University, Monterey Bay, Seafloor Mapping Lab 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 bathymetric contours of Offshore of Santa Cruz, 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?
    • Availability in digital form:
      Data format: The .zip file for a shapefile includes the .aux, .dbf, .shp, .shx, .sbx, and .sbn files, as well as the text (.txt) and XML (.shp.xml) versions of the metadata for the Contours data layer of Offshore Pigeon Point, California. in format SHP (version ArcMap (version 10.0, ESRI , 2011)) Point, line, and polygon features are in shapefile format and are projected in UTM Zone 10 coordinates, with datum WGS84. Size: 0.2
      Network links: https://www.sciencebase.gov/catalog/file/get/556e11ebe4b0d9246a9f9a7b
      http://pubs.usgs.gov/ds/781/
    • 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 an Esri ArcMap TIFF. Users should download the ArcGIS Project File, OffshoreSantaCruzGIS.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 Santa Cruz" 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: 22-Jun-2018
Metadata author:
Peter Dartnell
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
400 Natural Bridges Dr.
Santa Cruz, CA
USA

(831) 460-7415 (voice)
(831) 427-4709 (FAX)
pdartnell@usgs.gov
Metadata standard:
Content Standard for Digital Geospatial Metadata ("CSDGM version 2") (FGDC-STD-001-1998)

This page is <https://cmgds.marine.usgs.gov/catalog/pcmsc/cal_state_waters/Contours_OffshoreSantaCruz_metadata.faq.html>
Generated by mp version 2.9.49 on Wed Nov 28 12:14:57 2018