Title:Backscatter-Oregon OCS Floating Wind Farm Site Abstract:
This Data Release contains data from the U.S. Geological Survey (USGS) survey of the Oregon outer Continental shelf (OCS) Floating Wind Farm Site in 2014.
The backscatter intensity data was collected along with bathymetry data by USGS during the period from August 20 to September 1, 2014, using a Reson 7111 multibeam echosounder. The mapping mission collected bathymetry data from about 163 m to 566 m depths on the Oregon outer continental shelf. The acquisition was funded by the U.S. Bureau of Ocean Energy Management.
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).
Cochrane, Guy R., and Dartnell, Peter, 2015, Backscatter-Oregon OCS Floating Wind Farm Site: Data Release doi:10.5066/F7V40S8V, U.S. Geological Survey, Coastal and Marine Geology Program, Pacific Coastal and Marine Science Center, Santa Cruz, California.
Cochrane, Guy R., Dartnell, Peter, Hemery, Lenaig G., and Hatcher, Gerry, 2015, Data Release for USGS Field Activity 2014-607-FA, Oregon OCS Seafloor Mapping: Selected Lease Blocks Relevant to Renewable Energy: Data Release doi:10.5066/F7V40S8V, U.S. Geological Survey, Reston, VA.
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.
The Reson 7111 backscatter data that was processed by the USGS in 2014 was originally archived as an ESRI grid with the following attributes:
Cell size (X,Y) = 8.4645542, 8.4675282
Number of rows = 3759
Number of columns = 1988
Data type = integer
Xmin = 355165.874931
Xmax = 371993.408586
Ymin = 4793671.96784
Ymax = 4825501.4065
Minimum value = 1
Maximum value = 255
Mean = 152.87
Standard deviation = 24.94
Coordinate system description
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.
Multibeam mapping took place over 13 days from August 20 through September 1, 2014 (U.S. Geological Survey field activity 2014-607-FA). The survey was conducted using a 100-kHz Reson 7111 multibeam echosounder. The 7111 is a horseshoe shaped sonar that was mounted on the 34-foot USGS mapping vessel R/V Parke Snavely. The multibeam system receives acoustic returns from 101, 201, or 301 beams depending on the setting. Differentially Corrected Global Positioning System (DGPS) navigational data was used in combination with an Applanix Position and Motion Compensation System for Marine Vessels (POS/MV) to accurately position the vessel during data collection, and it also accounted for vessels motion such as heave, pitch, and roll. 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 processed to Mean Lower Low Water (MLLW) using tidal data from the Charleston, OR harmonic tide station (Station ID 9432780). Processed data were stored line-by-line as Reson S7K files.
Date: 2014 (process 2 of 4)
The multibeam-echosounder backscatter data were processed using the Fledermaus (version 7.3.2) integration of Geocoder. Caris HDCS line files were exported as GSF line files and imported into Fledermaus along with the corresponding original Reson S7K files. Adjustments were made to the line files including TX/RX (transmit/receive) power gain, beam pattern, and adaptive angle-varying gain corrections. The line files were then mosaiced into a 12-m resolution image. The image was then exported as a georeferenced TIFF image, imported into a GIS, and converted to a GRID at 12-m resolution.
Date: 21-Nov-2019 (process 3 of 4)
Edit was made to remove extraneous text from Semi Major Axis tag. Point of Contact and Metadata Contact were changed to PCMSC static contact. No data information was changed.
Person who carried out this activity:
Susan A. Cochran
U.S. Geological Survey, Pacific Coastal and Marine Science Center
2885 Mission St.
Santa Cruz, CA
Date: 19-Oct-2020 (process 4 of 4)
Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
Person who carried out this activity:
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.
USGS-authored or produced data and information are in the public domain from the U.S. Government and are freely redistributable with proper metadata and source attribution. Please recognize and acknowledge the U.S. Geological Survey as the originator(s) of the dataset and in products derived from these data. This information is not intended for navigation purposes.
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by 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 .zip file for the TIFF image includes the image (.tif) and associated files including the world registration file (.tfw), in addition to FGDC-compliant metadata and a browse graphic for the Backscatter bs_2014607FA data layer of the Oregon OCS.
in format TIFF
(version ArcMap (version 10.1))
Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system with datum WGS84.
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, OregonOCSArcMap.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 "Oregon OCS" 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.