BathymetryA Hillshade [USGS]--Offshore Aptos, California

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Frequently anticipated questions:


What does this data set describe?

Title: BathymetryA Hillshade [USGS]--Offshore Aptos, California
Abstract:
This part of DS 781 presents data for the bathymetry and shaded-relief maps of Offshore of Aptos map area, California. Bathymetry data are provided as two separate grids depending on mapping agency and processing method. The raster data files are included in "BathymetryAHS_USGS_OffshoreAptos.zip," which is accessible from http://dx.doi.org/10.5066/F7K35RQB. The bathymetry and shaded-relief maps of Offshore Aptos, California, were generated from bathymetry data collected by the U.S. Geological Survey (USGS) and by California State University, Monterey Bay (CSUMB). Mapping was completed between 2006 and 2009 using a combination of a 244-kHz Reson 8101 multibeam echosounder and a 234-kHz SEA SWATHplus bathymetric sidescan-sonar system. The mapping missions collected bathymetry data from about the 10-m isobath to beyond the 3-nautical-mile limit of California’s State Waters.
  1. How might this data set be cited?
    Dartnell, Peter, Ritchie, Andrew C., and Finlayson, David P., 2015, BathymetryA Hillshade [USGS]--Offshore Aptos, California:.

    This is part of the following larger work.

    Cochrane, Guy R., Johnson, Samuel Y., Dartnell, Peter, Greene, H. Gary, Erdey, Mercedes D., Dieter, Bryan E., Golden, Nadine E., Hartwell, Stephen R., Ritchie, Andrew C., Kvitek, Rikk G., Maier, Katherine L., Endris, Charles A., Davenport, Clifton W., Watt, Janet T., Sliter, Ray W., Finlayson, David P., and Krigsman, Lisa M., 2015, California State Waters Map Series--Offshore of Aptos Map Area, California: U.S. Geological Survey data set F7PV6HD9, U.S. Geological Survey, Reston, VA.

    Online Links:

  2. What geographic area does the data set cover?
    West_Bounding_Coordinate: -122.00
    East_Bounding_Coordinate: -121.80
    North_Bounding_Coordinate: 37.00
    South_Bounding_Coordinate: 36.84
  3. What does it look like?
    https://www.sciencebase.gov/catalog/file/get/5576269de4b032353caef2b1?f=__disk__bb%2F10%2F83%2Fbb1083986ef06814056f4ef56f4467ced776d800&allowOpen=true (JPEG)
    Hillshaded bathymetry map of offshore Aptos.
  4. Does the data set describe conditions during a particular time period?
    Beginning_Date: 2006
    Ending_Date: 2009
    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 8806 x 8916 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
    BathymetryA [USGS] hillshade intensity value (Source: ESRI)
    VALUE
    Bathymetry hillshade intensity values (Source: ESRI)
    Range of values
    Minimum:0
    Maximum:254
    Units:Integers from 0-254 representing hillshaded bathymetry

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)
    • Peter Dartnell
    • Andrew C. Ritchie
    • 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
    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) from unintended targets in the water column. Finally, the soundings were converted into 2-m-resolution bathymetric-surface-model grids. Person who carried out this activity:
    Pete 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: 2014 (process 2 of 4)
    California State University, Monterey Bay, Seafloor Mapping Lab 3-m resolution bathymetry data (SoCy_3mbathy) within this map were downloaded from California State University, Monterey Bay, Seafloor Mapping Lab (http://seafloor.csumb.edu/SFMLwebDATA.htm). Clip 3-m resolution bathymetry grid to the Offshore Aptos, California, map boundary. Clip USGS 2-m resolution bathymetry grid to the Offshore Aptos, California, map boundary. These grids were not merged and are provided as separate grids. To create the shaded-relief imagery, an illumination having an azimuth of 300 degrees and 45 degrees above the horizon was applied to the bathymetry grid. Person who carried out this activity:
    Pete 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 3 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 4 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
  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 bathymetry and shaded-relief maps of Offshore of Aptos, 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 the TIFF image includes the image (.tif), the world registration file (.tfw), and the text (.txt) and XML (.tif.xml) versions of the metadata for the BathymetryAHS [USGS] data layer of Offshore Aptos, California. in format TIFF (version ArcMap (version 10.0, ESRI , 2011)) Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system with datum WGS84. Size: 15.5
      Network links: https://www.sciencebase.gov/catalog/file/get/556f79dfe4b0d9246a9fd086
      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, OffshoreAptosGIS.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 Aptos" 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: 26-Apr-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/BathymetryAHS_USGS_OffshoreAptos_metadata.faq.html>
Generated by mp version 2.9.49 on Mon Sep 10 17:43:32 2018