Backscatter B [7125]--Offshore Half Moon Bay, California

Metadata:

• Identification_Information
• Data_Quality_Information
• Spatial_Data_Organization_Information
• Spatial_Reference_Information
• Entity_and_Attribute_Information
• Metadata_Reference_Information

Identification_Information:

Citation:

Citation_Information:

Originator: Carrie K. Bretz

Originator: Rikk G. Kvitek

Originator: Peter Dartnell

Originator: Eleyne L. Phillips

Publication_Date: 2014

Title: Backscatter B [7125]--Offshore Half Moon Bay, California

Edition: 1.0

Geospatial_Data_Presentation_Form: GeoTiff

Larger_Work_Citation:

Citation_Information:

Originator: Guy R. Cochrane

Originator: Peter Dartnell

Originator: H. Gary Greene

Originator: Samuel Y. Johnson

Originator: Nadine E. Golden

Originator: Stephen R. Hartwell

Originator: Brian E. Dieter

Originator: Michael W. Mansion

Originator: Ray W. Sliter

Originator: Stephanie L. Ross

Originator: Janet T. Watt

Originator: Charles A. Endris

Originator: Rikk G. Kvitek

Originator: Brian D. Edwards

Originator: Eleyne L. Phillips

Originator: Mercedes D. Erdey

Originator: Carrie K. Bretz

Originator: John L. Chin

Originator: Carrie K. Bretz

Publication_Date: 2014

Title:

California State Waters Map Series--Offshore of Half Moon Bay map area, California

Geospatial_Data_Presentation_Form: map

Series_Information:

Series_Name: Open-File Report

Issue_Identification: OFR 2014-1214

Publication_Information:

Publication_Place: Reston, VA

Publisher: U.S. Geological Survey

Online_Linkage: <https://pubs.usgs.gov/of/2014/1214/>

Larger_Work_Citation:

Citation_Information:

Originator: Nadine E. Golden

Publication_Date: 2013

Title: California State Waters Map Series Data Catalog

Geospatial_Data_Presentation_Form: database

Series_Information:

Series_Name: Data Series

Issue_Identification: DS 781

Publication_Information:

Publication_Place: Reston, VA

Publisher: U.S. Geological Survey

Online_Linkage: <https://pubs.usgs.gov/ds/781/>

Description:

Abstract:

This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Half Moon Bay map area, California. Backscatter data are provided as two separate grids depending on mapping system (Reson 7125 and Reson 8101). The raster data file is included in "BackscatterB_7125_OffshoreHalfMoonBay.zip," which is accessible from <https://pubs.usgs.gov/ds/781/OffshoreHalfMoonBay/data_catalog_OffshoreHalfMoonBay.html>.

The acoustic-backscatter map of the Offshore of Half Moon Bay, California was generated from backscatter data collected by Fugro Pelagos and by California State University, Monterey Bay (CSUMB). Mapping was completed in 2006 and 2007, using a combination of 400-kHz Reson 7125 and 244-kHz Reson 8101 multibeam echosounders. 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).

Purpose:

These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes. These data can be used with geographic information systems or other software.

Time_Period_of_Content:

Time_Period_Information:

Range_of_Dates/Times:

Beginning_Date: 2006

Ending_Date: 2007

Currentness_Reference: ground condition

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -122.60

East_Bounding_Coordinate: -122.39

North_Bounding_Coordinate: 37.54

South_Bounding_Coordinate: 37.38

Keywords:

Theme:

Theme_Keyword_Thesaurus: Global Change Master Directory (GCMD)

Theme_Keyword: Oceans > Bathymetry/SeafloorTopography > Bathymetry

Theme_Keyword: Oceans > Bathymetry/SeafloorTopography > Seafloor Topography

Theme:

Theme_Keyword_Thesaurus: General

Theme_Keyword: Marine Geology

Theme_Keyword: Multibeam

Theme_Keyword: Geology

Theme_Keyword: Bathymetry

Theme_Keyword: Backscatter

Theme_Keyword: Intensity

Theme_Keyword: Ocean Floor Topography

Theme_Keyword: U.S. Geological Survey

Theme_Keyword: USGS

Theme_Keyword: Pacific Coastal and Marine Science Center

Theme_Keyword: CSMP

Theme:

Theme_Keyword_Thesaurus: ISO 19115 Topic Category

Theme_Keyword: geoscientificInformation

Theme_Keyword: imageryBaseMapsEarthCover

Theme_Keyword: oceans

Place:

Place_Keyword_Thesaurus: Geographic Names Information System (GNIS)

Place_Keyword: Half Moon Bay

Place_Keyword: State of California

Access_Constraints: None

Use_Constraints:

Please recognize the U.S. Geological Survey (USGS) and California State University, Monterey Bay, Seafloor Mapping Lab (CSUMB). USGS-authored or produced data and information are in the public domain.
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_Person_Primary:

Contact_Person: Peter Dartnell

Contact_Organization:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Contact_Position: Physical Scientist

Contact_Address:

Address_Type: mailing and physical address

Address: 400 Natural Bridges Dr.

City: Santa Cruz

State_or_Province: CA

Postal_Code: 95060-5792

Country: USA

Contact_Voice_Telephone: (831) 460-7415

Contact_Facsimile_Telephone: (831) 427-4709

Contact_Electronic_Mail_Address: pdartnell@usgs.gov

Browse_Graphic:

Browse_Graphic_File_Name:

<https://pubs.usgs.gov/ds/781/OffshoreHalfMoonBay/images/BackscatterB_7125_OffshoreHalfMoonBay.jpg>

Browse_Graphic_File_Description: Acoustic backscatter imagery of offshore Half Moon Bay.

Browse_Graphic_File_Type: JPEG

Data_Quality_Information:

Attribute_Accuracy:

Attribute_Accuracy_Report: Not applicable for raster data.

Logical_Consistency_Report: Unspecified

Completeness_Report: Complete

Positional_Accuracy:

Horizontal_Positional_Accuracy:

Horizontal_Positional_Accuracy_Report:

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.

Vertical_Positional_Accuracy:

Vertical_Positional_Accuracy_Report:

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.

Lineage:

Process_Step:

Process_Description:

During the mapping missions, an Applanix position and motion compensation system (POS/MV) was used to accurately position the vessel during data collection, and it also accounted for vessel motion such as heave, pitch, and roll (position accuracy, ±2 m; pitch, roll, and heading accuracy, ±0.02 degress; heave accuracy, ±5 percent, or 5 cm). KGPS altitude data (Fugro Pelagos, StarFix HP & XP units; CSUMB, NavCom 2050) were used to account for tide cycle fluctuations and sound velocity profiles were collected with an Applied Microsystems SVPlus sound velocimeter. Soundings were corrected for vessel motion using the Applanix POS/MV 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 the KGPS receivers. Backscatter data were processed using Geocoder Version 3.2 (Fugro Pelagos Modified Test Release 16). Within 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. After the lines were imported, they were mosaicked into a 1m resolution image. Overlap between parallel lines was resolved using a priority table based on the distance of each sample from the ship track, with samples closest to- and furthest from- the ship track given the lowest priority. An anti-aliasing algorithm was also applied.

Process_Date: 2007

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Carrie Bretz

Contact_Organization: Seafloor Mapping Lab, California State University Monterey Bay

Contact_Position: Projects Manager, GIS; Metadata Supervisor

Contact_Address:

Address_Type: mailing and physical address

Address: 100 Campus Center, Bldg 13

City: Seaside

State_or_Province: CA

Postal_Code: 93955

Country: USA

Contact_Voice_Telephone: (831) 582-4197

Contact_Electronic_Mail_Address: carrie_bretz@csumb.edu

Process_Step:

Process_Description:

California Seafloor Mapping Project 1- and 2-m resolution backscatter imagery (CSMP survey blocks CC-03, CC-05, CC-06, and CC-07) within this map were downloaded from California State University, Monterey Bay, Seafloor Mapping Lab (<http://seafloor.csumb.edu/SFMLwebDATA.htm>) and converted to grids. Backscatter grids of similar mapping systems were merged 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.

Process_Date: 2009

Process_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Pete Dartnell

Contact_Organization:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Contact_Position: Physical Scientist

Contact_Address:

Address_Type: mailing and physical address

Address: 400 Natural Bridges Dr.

City: Santa Cruz

State_or_Province: CA

Postal_Code: 95060-5792

Country: USA

Contact_Voice_Telephone: (831) 460-7415

Contact_Electronic_Mail_Address: pdartnell@usgs.gov

Spatial_Data_Organization_Information:

Direct_Spatial_Reference_Method: Raster

Raster_Object_Information:

Raster_Object_Type: Grid Cell

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: -123.00000

Latitude_of_Projection_Origin: 0.00000

False_Easting: 500000.0

False_Northing: 0.00

Planar_Coordinate_Information:

Planar_Coordinate_Encoding_Method: coordinate pair

Coordinate_Representation:

Abscissa_Resolution: 2.0

Ordinate_Resolution: 2.0

Planar_Distance_Units: Meters

Geodetic_Model:

Horizontal_Datum_Name: WGS84

Ellipsoid_Name: WGS84

Semi-major_Axis: 6378137.00 meters

Denominator_of_Flattening_Ratio: 298.257223563

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

The merged Reson 7125 acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:

Cell size = 2.0
Number of rows = 8980
Number of columns = 8975

Data type = floating point

Boundary
Xmin = 535610
Xmax = 553560
Ymin = 4137800
Ymax = 4155760

Statistics
Minimum value = 0
Maximum value = 254
Mean = 146.63
Standard deviation = 34.77

Coordinate system description
Projection  UTM
Zone  10
Datum  WGS84
Units  meter

The merged Reson 8101 acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:

Cell size = 2.0
Number of rows = 8980
Number of columns = 8975

Data type = floating point

Boundary
Xmin = 535600
Xmax = 553540
Ymin = 4137780
Ymax = 4155740

Statistics
Minimum value = 0
Maximum value = 254
Mean = 151.33
Standard deviation = 55.38

Coordinate system description
Projection  UTM
Zone  10
Datum  WGS84
Units  meter

Entity_and_Attribute_Detail_Citation: none

Metadata_Reference_Information:

Metadata_Date: 20130617

Metadata_Review_Date: 20140821

Metadata_Contact:

Contact_Information:

Contact_Person_Primary:

Contact_Person: Peter Dartnell

Contact_Organization:

U.S. Geological Survey, Pacific Coastal and Marine Science Center

Contact_Position: Physical Scientist

Contact_Address:

Address_Type: mailing and physical address

Address: 400 Natural Bridges Dr.

City: Santa Cruz

State_or_Province: CA

Postal_Code: 95060-5792

Country: USA

Contact_Voice_Telephone: (831) 460-7415

Contact_Facsimile_Telephone: (831) 427-4709

Contact_Electronic_Mail_Address: pdartnell@usgs.gov

Metadata_Standard_Name:

Content Standard for Digital Geospatial Metadata ("CSDGM version 2")

Metadata_Standard_Version: FGDC-STD-001-1998

Metadata_Time_Convention: universal time