Backscatter--Offshore of Refugio Beach Area, 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: Peter Dartnell

Originator: Eleyne L. Phillips

Originator: David P. Finlayson

Publication_Date: 2015

Title: Backscatter--Offshore of Refugio Beach Area, California

Edition: 1.0

Geospatial_Data_Presentation_Form: GeoTiff

Larger_Work_Citation:

Citation_Information:

Originator: Samuel Y. Johnson

Originator: Peter Dartnell

Originator: Guy R. Cochrane

Originator: Nadine E. Golden

Originator: Eleyne L. Phillips

Originator: Andrew C. Ritchie

Originator: Lisa M. Krigsman

Originator: Bryan E. Dieter

Originator: James E. Conrad

Originator: H. Gary Greene

Originator: Gordon G. Seitz

Originator: Charles A. Endris

Originator: Ray W. Sliter

Originator: Florence L. Wong

Originator: Mercedes D. Erdey

Originator: Carlos I. Gutierrez

Originator: Mary M. Yoklavich

Originator: Amy E. Draut

Originator: Patrick E. Hart

Publication_Date: 2015

Title:

California State Waters Map Series--Offshore of Refugio Beach Area, California

Geospatial_Data_Presentation_Form: map

Series_Information:

Series_Name: Scientific Investigations Map

Issue_Identification: SIM 3319

Publication_Information:

Publication_Place: Reston, VA

Publisher: U.S. Geological Survey

Online_Linkage: <https://pubs.usgs.gov/sim/3319/>

Online_Linkage: <https://dx.doi.org/10.3133/sim3319>

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 SIM 3319 presents data for part of the acoustic-backscatter map (see sheet 3, SIM 3319) of Offshore Refugio Beach map area, California. The raster data file is included in "Backscatter_OffshoreRefugioBeach.zip," which is accessible from <https://pubs.usgs.gov/ds/781/OffshoreRefugioBeach/data_catalog_OffshoreRefugioBeach.html>.
The acoustic-backscatter map of Offshore Refugio Beach Area was generated from backscatter data collected by the U.S. Geological Survey (USGS). The USGS mapped this region in the summer 2008 using a 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. These data were later re-processed in 2012. Within the acoustic-backscatter 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 sediment type. 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. These data can be used with geographic information systems or other software.

Supplemental_Information:

Information for the related USGS Pacific Coastal and Marine Science Center data collection field activities, S-8-08-SC online at <http://walrus.wr.usgs.gov/infobank/s/s808sc/html/s-8-08-sc.meta.html>.

Time_Period_of_Content:

Time_Period_Information:

Single_Date/Time:

Calendar_Date: 2015

Currentness_Reference: Publication Date

Status:

Progress: Complete

Maintenance_and_Update_Frequency: As needed

Spatial_Domain:

Bounding_Coordinates:

West_Bounding_Coordinate: -120.19

East_Bounding_Coordinate: -119.99

North_Bounding_Coordinate: 34.55

South_Bounding_Coordinate: 34.38

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: Santa Barbara Channel

Place_Keyword: Refugio Beach

Place_Keyword: Pacific Ocean

Place_Keyword: State of California

Access_Constraints: None

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_Person_Primary:

Contact_Person: Peter Dartnell

Contact_Organization:

U.S. Geological Survey, Pacifc 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/OffshoreRefugioBeach/images/Backscatter_OffshoreRefugioBeach.jpg>

Browse_Graphic_File_Description: Acoustic backscatter imagery of offshore Refugio Beach.

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 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: Not applicable

Lineage:

Process_Step:

Process_Description:

USGS backscatter data were collected in 2008 using a 234.5 kHz SEA (AP) Ltd. SWATHplus-M phase-differencing sidescan sonar. During the USGS mapping mission, Real Time Kinematic (RTK) GPS data and measurements of vessel motion (heave, pitch, and roll) were combined in a CodaOctopus F190 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 working with previously measured sound-velocity profiles. Statistical filters were applied to the raw samples that discriminate the seafloor returns (soundings and backscatter) from other unintended targets in the water column.

Process_Date: 2008

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

Process_Step:

Process_Description:

Raw shipbord SWATHplus line files were post-processed using USGS software (D.P. Finlayson, 2011, written comm.) that normalizes for time-varying signal loss and beam directivity differences. Thus, the raw 16-bit backscatter data were gain-normalized to enhance the backscatter of the SWATHplus system. The resulting normalized-amplitude values were rescaled to 16-bit and gridded using GRID Processor Software, then imported into a GIS and converted to GRIDS.

Process_Date: 2012

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: NAVD88

Semi-major_Axis: 6378137.00 meters

Denominator_of_Flattening_Ratio: 298.257223563

Entity_and_Attribute_Information:

Overview_Description:

Entity_and_Attribute_Overview:

The Offshore Refugio Beach backscatter grid was originally archived as an ESRI grid with the following attributes:

Cell size = 2.0
Number of rows = 8960
Number of columns = 8960

Data type = floating point

Boundary
Xmin = 758070.0
Xmax = 775990.0
Ymin = 3808160.0
Ymax = 3826080.0

Statistics
Minimum value = 0
Maximum value = 65535.0
Mean = 32539.330
Standard deviation = 7803.45

Coordinate system description
Projection  UTM
Zone  10
Datum  WGS84
Units  meter

Entity_and_Attribute_Detail_Citation: none

Metadata_Reference_Information:

Metadata_Date: 20121129

Metadata_Review_Date: 20121129

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