Identification_Information:
  Citation:
    Citation_Information:
      Originator: U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), Santa Cruz, CA.
      Publication_Date: 2014
      Title: April 2012 bathymetry (WGS84) of Coyote Creek and Alviso Slough, South San Francisco Bay, California
      Geospatial_Data_Presentation_Form: raster digital data
      Larger_Work_Citation:
        Citation_Information:
          Originator: U.S. Geological Survey (USGS), Pacific Coastal and Marine Science Center (PCMSC), Santa Cruz, CA.
          Publication_Date: 2014
          Title: Bathymetry and Digital Elevation Models of Coyote Creek and Alviso Slough, South San Francisco Bay, California (Version 2, Revised March 2014)
          Edition: Version 2.0
          Series_Information:
            Series_Name: U.S. Geological Survey Open-File Report
            Issue_Identification: OF2011-1315
          Online_Linkage: http://pubs.usgs.gov/of/2011/1315, http://dx.doi.org/10.3133/ofr20111315
  Description:
    Abstract:
      1-m resolution bathymetry collected in Coyote Creek and Alviso Slough in April 2012.

      Projection = UTM Zone 10 in meters
      Horizontal Datum = WGS84(G1150)
      Elevations relative to the WGS84 Ellipsoid, all units in meters.

      The surveys extend east from Calaveras Point along Coyote Creek to the railroad bridge,
      along Alviso Slough to the town of Alviso (just over 7 km), and along the 3.7 km of Guadalupe
      Slough closest to the bay.
    Purpose:
      To monitor bathymetric change as the South Bay Salt Pond Restoration Project progresses
      (http://www.southbayrestoration.org).
    Supplemental_Information:
      USGS Field Activity S-03-12-SF
      http://walrus.wr.usgs.gov/infobank/s/s0312sf/html/s-03-12-sf.meta.html
  Time_Period_of_Content:
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 20120402
        Ending_Date: 20120406
    Currentness_Reference: ground condition
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: As needed
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: -122.060187436
      East_Bounding_Coordinate: -121.974560855
      North_Bounding_Coordinate: 37.4706742088
      South_Bounding_Coordinate: 37.4231662547
  Keywords:
    Theme:
      Theme_Keyword_Thesaurus: ISO 19115 Topic Category
      Theme_Keyword: elevation
      Theme_Keyword: geoscientificInformation
      Theme_Keyword: inlandWaters
      Theme_Keyword: oceans
    Theme:
      Theme_Keyword_Thesaurus: GCMD SCIENCE PARAMETERS
      Theme_Keyword: OCEANS > BATHYMETRY > SEAFLOOR TOPOGRAPHY > BATHYMETRY
    Theme:
      Theme_Keyword_Thesaurus: GCMD INSTRUMENT PARAMETERS
      Theme_Keyword: SIDE-SCAN SONAR
      Theme_Keyword: GPS > Global Positioning System
      Theme_Keyword: LIDAR > Light Detection and Ranging
    Place:
      Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)
      Place_Keyword: State of California
      Place_Keyword: San Francisco Bay
      Place_Keyword: Alameda County
      Place_Keyword: Santa Clara County
      Place_Keyword: Alviso
      Place_Keyword: Coyote Creek
      Place_Keyword: Alviso Slough
      Place_Keyword: Guadalupe Slough
  Access_Constraints:
    If physical samples or materials are available, constraints on their on-site access are described in "WR CMG
    Sample Distribution Policy" at URL:
    http://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html
  Use_Constraints:
    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.

    Acknowledge the U.S. Geological Survey in products derived
    from these data. Share data products developed using these
    data with the U.S. Geological Survey.

    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.
  Point_of_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: USGS Pacific Coastal and Marine Science Center
        Contact_Person: David P Finlayson
      Contact_Position: Operational Geologist
      Contact_Address:
        Address_Type: physical address
        Address: 400 Natural Bridges Drive
        City: Santa Cruz
        State_or_Province: CA
        Postal_Code: 95060
        Country: USA
      Contact_Voice_Telephone: (831) 460-7557
      Contact_Facsimile_Telephone: (831) 427-4748
      Contact_Electronic_Mail_Address: dfinlayson@usgs.gov
  Browse_Graphic:
    Browse_Graphic_File_Name: <http://walrus.wr.usgs.gov/infobank/s/s0312sf/html/s-03-12-sf.nav.jpg>
    Browse_Graphic_File_Description: Image showing S-03-12-SF survey tracklines.
    Browse_Graphic_File_Type: JPEG
Data_Quality_Information:
  Attribute_Accuracy:
    Attribute_Accuracy_Report: This bathymetric data has not been independently verified for accuracy.
  Logical_Consistency_Report: All bathymetric values are derived from the same instruments and processing workflow.
  Completeness_Report:
    The raw bathymetry data was filtered in SEA Swath Processor and imported into CARIS HIPS and SIPS for post-processing.
    Within CARIS a swath angle BASE (Bathymetric with Associated Statistical Error) surface was created at 1 m resolution and the
    subset editor used to manually eliminate any remaining outliers or artifacts. The average depth within each 1 by 1 m cell was exported
    as an ASCII text file and imported into Surfer for interpolation using a linear kriging algorithm with a 1-simga nugget of 0.05 m and a
    2 by 2 m search radius.  The resultant grid was exported to ESRI ArcMap software for display.
  Positional_Accuracy:
    Horizontal_Positional_Accuracy:
      Horizontal_Positional_Accuracy_Report:
        Uncertainty in the horizontal position of each sounding is a function of the total uncertainty propagated through
        each of the following component instruments: 1) base station GPS, 2) vessel GPS, 3) intertial
        motion unit (IMU), 4) water sound velocity model, and 5) beam spreading in the water column.  Assuming no
        systematic errors in the measurement instruments themselves, beam spreading is the dominate source
        of positional uncertainty. The 1-degree sonar beam of the SWATHplus-M results in horizontal uncertainty ranging
        from 0.10 m at 10 m slant range, to about 0.45 m at 50 m slant range.
    Vertical_Positional_Accuracy:
      Vertical_Positional_Accuracy_Report:
        After filtering the data to remove obvious outliers, the standard deviation of the remaining sounding elevations
        was calculated for each 1 m by 1 m cell (each containing 19 soundings on average) in CARIS. The mean
        of the standard deviation for all cells in the  survey is 0.05 m and 97% of the cells in the data set have a
        standard deviation of less than 0.15 m.
  Lineage:
    Source_Information:
      Source_Citation:
        Citation_Information:
          Originator: U.S. Geological Survey, Coastal and Marine Geology Program
          Publication_Date: 2012
          Title: USGS CMG Field Activity S-03-12-SF
          Geospatial_Data_Presentation_Form: raster digital data
          Online_Linkage: <http://walrus.wr.usgs.gov/infobank/s/s0312sf/html/s-03-12-sf.meta.html>
      Type_of_Source_Media: online
      Source_Time_Period_of_Content:
        Time_Period_Information:
          Range_of_Dates/Times:
            Beginning_Date: 20120402
            Ending_Date: 20120406
        Source_Currentness_Reference: ground condition
      Source_Citation_Abbreviation: S-03-12-SF
      Source_Contribution: This 2012 field activity collected bathymetric data in San Francisco Bay.
    Process_Step:
      Process_Description:
        Sonar Data Collection

        The bathymetric surveys were conducted using a 234.5 kHz SEA (Systems Engineering & Assessment Ltd)
        SWATHplus-M phase-differencing sidescan sonar. The sonar was pole-mounted on the 34-foot USGS
        mapping vessel R/V Parke Snavely, and affixed to a hull brace. Real-time kinematic (RTK) GPS position data
        were passed through a CodaOctopus F180 intertial measurement unit (IMU) to the sonar hardware and data
        collection software. Sonar heads, GPS antennae, and the IMU were surveyed in place to a common reference
        frame with a Geodimeter 640 Total Station. The R/V Snavely was outfitted with three networked workstations
        and a navigation computer for use by the captain and survey crew for data collection and initial processing.
      Process_Date: 2012
    Process_Step:
      Process_Description:
        Geodetic Control

        Geodetic control for the survey was established using a shore based Global Positioning System (GPS) base
        station broadcasting Real Time Kinematic (RTK) corrections to the survey vessel via UHF radio link. The base
        station was located at Moffett Naval Air Station, on a pre-existing benchmark identified as ARC 34.  The NGS
        lists this monument as PID DG6881 (See Appendix A in report for NGS Datasheet).

        GPS base station coordinates:
        Reference Frame: NAD83 (NSRS2007)
        Epoch Date: 2007.00
        Latitude: N 37 degrees 25' 34.57880"
        Longitude: W 122 degrees 02' 05.53373"
        Orthometric Height: 1.280 m (NAVD88 height modernization project elevation)
      Process_Date: 2012
    Process_Step:
      Process_Description:
        Vessel Position and Attitude

        The R/V Snavely was equipped with a CodaOctopus F180 attitude and positioning system for the duration of
        the survey. The F180 is running F190 firmware, and receives real-time kinematic (RTK) corrections directly.
        The RTK GPS data (2 cm error ellipse) are combined with the inertial motion measurements directly within the
        F190 hardware so that high-precision position and attitude corrections are fed in real-time to the sonar
        acquisition equipment. The NAD83 (NSRS2007) Epoch 20007.00 3-dimensional reference frame was used for
        all data acquisition.
      Process_Date: 2012
    Process_Step:
      Process_Description:
        Sound Velocity Measurements

        Sound velocity measurements were collected continuously with an Applied Micro Systems Micro SV deployed
        on the transducer frame for real-time sound velocity adjustments at the transducer-water interface. The Micro
        SV is accurate to +/- 0.03 m/s. In addition, sound velocity profiles (SVP) were collected with an Applied Micro
        Systems, SvPlus 3472. This instrument provides time-of-flight sound-velocity measurements by using invar rods
        with a sound-velocity accuracy of +/- 0.06 m/s, pressure measured by a semiconductor bridge strain gauge to an
        accuracy of 0.15 percent (Full Scale) and temperature measured by thermistor to an accuracy of 0.05 degrees
        Celsius (Applied Microsystems Ltd., 2005).
      Process_Date: 2012
    Process_Step:
      Process_Description:
        Sonar Sounding Processing

        GPS data and measurements of vessel motion are combined in the F180 hardware to produce a
        high-precision vessel attitude packet. This packet is transmitted to the Swath Processor acquisition
        software in real-time and combined with instantaneous sound velocity measurements at the transducer
        head before each ping. Up to 20 pings per second are transmitted with each ping consisting of 2048 samples
        per side (port and starboard). The returned samples are projected to the seafloor using a ray-tracing algorithm
        working with the previously measured sound velocity profiles in SEA Swath Processor (version 3.05.18.04). A
        series of statistical filters are applied to the raw samples that isolate the seafloor returns from other
        uninteresting targets in the water column. Finally, the processed data is stored line-by-line in both raw (.sxr)
        and processed (.sxp) trackline files. Processed (.sxp) files were further processed with sxpegn (build 151) by
        Amy Foxgrover (USGS) to remove erroneous data from the files and make valid gain-normalized amplitude
        data for processing backscatter data.
      Process_Date: 2012
    Process_Step:
      Process_Description:
        Digital Elevation Model Production

        The raw bathymetry data was filtered in SEA Swath Processor and imported into CARIS HIPS and SIPS for post-processing.
        Within CARIS a swath angle BASE (Bathymetric with Associated Statistical Error) surface was created at 1 m resolution and the
        subset editor used to manually eliminate any remaining outliers or artifacts. The average depth within each 1 by 1 m cell was exported
        as an ASCII text file and imported into Surfer for interpolation using a linear kriging algorithm with a 1-simga nugget of 0.05 m and a
        2 by 2 m search radius.  The resultant grid was exported to ESRI ArcMap software for display and further analyses.  The entire survey was
        deepened by 6 cm to account for a bias resulting from changes in the boat instrumentation configuration that occured since the initial survey
        was collected in 2010.

        To convert the data from orthometric heights NAD83 (NSRS2007)/NAVD88 to ellipsoid heights on WGS84 (G1150, also known
        as ITRF2000), the 1 meter-grid resolution data was exported to an X,Y,Z point file.  NOAA's VDatum Version 2.3.0
        (CO-OPS, 2010) was used to apply Geoid09 (NGS, 2009) and convert the orthometric height data into ellipsoid heights
        on the NAD83 (NSRS2007) ellipsoid. The data was next transformed from the NAD83 (NSRS2007) ellipsoid to the WGS84(G1150)
        ellipsoid using a 14-point Helmert transformation described in Soler and Snay (2004) using the command line tool CS2CS
        in the Proj4 library (http://trac.osgeo.org/proj/). The parameters were calculated for an Epoch date of 2007.0000
      Process_Date: 2012
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: raster
  Raster_Object_Information:
    Raster_Object_Type: grid cell
    Row_Count: 4978
    Column_Count: 7466
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Grid_Coordinate_System:
        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
            Latitude_of_Projection_Origin: 0.0
            False_Easting: 500000
            False_Northing: 0.0
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: row and column
        Coordinate_Representation:
          Abscissa_Resolution: 1.0
          Ordinate_Resolution: 1.0
        Planar_Distance_Units: meters
    Geodetic_Model:
      Horizontal_Datum_Name: WGS84
      Ellipsoid_Name: WGS84 (G1150)
      Semi-major_Axis: 6378137
      Denominator_of_Flattening_Ratio: 298.257
  Vertical_Coordinate_System_Definition:
    Altitude_System_Definition:
      Altitude_Datum_Name: WGS84
      Altitude_Resolution: 0.01
      Altitude_Distance_Units: meters
      Altitude_Encoding_Method: Attribute values
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: Altitude
      Entity_Type_Definition: Altitude (elevation) above the WGS84 (G1150) ellipsoid in meters. Values are positive up.
      Entity_Type_Definition_Source: USGS Open-File Report: 2011-1315
Distribution_Information:
  Distributor:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: U.S. Geological Survey, Pacific Coastal and Marine Science Center (PCMSC)
        Contact_Person: David P Finlayson
      Contact_Address:
        Address_Type: mailing and physical address
        Address: 400 Natural Bridges Drive
        City: Santa Cruz
        State_or_Province: CA
        Postal_Code: 95060-5792
        Country: US
      Contact_Voice_Telephone: 831-460-7557
      Contact_Facsimile_Telephone: 831-427-4748
      Contact_Electronic_Mail_Address: dfinlayson@usgs.gov
  Resource_Description: Downloadable Data
  Distribution_Liability:
    This information is not intended for navigational purposes.

    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.

    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.
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Format_Name: ESRI ASCII Grid
        Format_Version_Number: 1.0
        Format_Information_Content:
          The ASCII file consists of header information containing a set of keywords, followed by cell values in row-major
          order. The file format is:
          >
          ><NCOLS xxx>
          ><NROWS xxx>
          ><XLLCENTER xxx | XLLCORNER xxx>
          ><YLLCENTER xxx | YLLCORNER xxx>
          ><CELLSIZE xxx>
          >{NODATA_VALUE xxx}
          >row 1
          >row 2
          >.
          >.
          >.
          >row n
          >
          where xxx is a number, and the keyword nodata_value is optional and defaults to -9999. Row 1 of the data is
          at the top of the grid, row 2 is just under row 1 and so on. The nodata_value is the value in the ASCII file to be
          assigned to those cells whose true value is unknown. In the grid they will be assigned the keyword NODATA.
          Cell values are be delimited by spaces. No carriage returns are necessary at the end of each row in the grid
          (although they are included in this case). The number of columns in the header is used to determine when a
          new row begins. The number of cell values is equal to the number of rows times the number of columns.
        Transfer_Size: 30
      Digital_Transfer_Option:
        Online_Option:
          Computer_Contact_Information:
            Network_Address:
              Network_Resource_Name: http://pubs.usgs.gov/of/2011/1315/, http://dx.doi.org/10.3133/ofr20111315
    Fees: No cost
Metadata_Reference_Information:
  Metadata_Date: 2015
  Metadata_Contact:
    Contact_Information:
      Contact_Person_Primary:
        Contact_Person: Amy Foxgrover
      Contact_Address:
        Address_Type: mailing address
        Address: 400 Natural Bridges Drive
        City: Santa Cruz
        State_or_Province: California
        Postal_Code: 95060
        Country: USA
      Contact_Voice_Telephone: (831) 460-7561
      Contact_Electronic_Mail_Address: afoxgrover@usgs.gov
  Metadata_Standard_Name: Content Standard for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998