Peter Dartnell
Rikk G. Kvitek
2014
Backscatter B [7125]--Offshore of Bodega Head, California
1.0
GeoTiff
Data Series
DS 781
Reston, VA
U.S. Geological Survey
https://doi.org/10.3133/ds781
https://pubs.usgs.gov/ds/781/OffshoreBodegaHead/data_catalog_OffshoreBodegaHead.html
Nadine E. Golden
2013
California State Waters Map Series Data Catalog
database
Data Series
DS 781
Reston, VA
U.S. Geological Survey
https://doi.org/10.3133/ds781
This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bodega Head map area, California. Backscatter data are provided as separate grids depending on mapping system or processing method. The raster data file is included in "BackscatterB_7125_OffshoreBodegaHead.zip", which is accessible from https://pubs.usgs.gov/ds/781/OffshoreBodegaHead/data_catalog_OffshoreBodegaHead.html. These data accompany the pamphlet and map sheets of Johnson, S.Y., Dartnell, P., Golden, N.E., Hartwell, S.R., Erdey, M.D., Greene, H.G., Cochrane, G.R., Kvitek, R.G., Manson, M.W., Endris, C.A., Dieter, B.E., Watt, J.T., Krigsman, L.M., Sliter, R.W., Lowe, E.N., and Chin, J.L. (S.Y. Johnson and S.A. Cochran, eds.), 2015, California State Waters Map Series—Offshore of Bodega Head, California: U.S. Geological Survey Open-File Report 2015–1140, pamphlet 39 p., 10 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20151140.
The acoustic-backscatter map of the Offshore of Bodega Head map area, California, was generated from backscatter data collected by California State University, Monterey Bay (CSUMB), and by Fugro Pelagos. Mapping was completed between 2007 and 2010, using a combination of 200-kHz and 400-kHz Reson 7125, and 244-kHz Reson 8101 multibeam echosounders, as well as 468-kHz SEA SWATHPlus interferometric system. These mapping missions combined to collect backscatter data (sheet 3) from about the 10-m isobath to beyond the 3-nautical-mile limit of California State Waters. 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 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). These data are not intended for navigational purposes.
To expand geologic mapping to the seafloor within the California's State
Waters, to update coastal geologic mapping, and to contribute to a uniform regional geologic database, which can be used geographic information systems.
Additionally, to provide a geologic map for the public and geoscience community to aid in assessments and mitigation of geologic hazards in the Bodega Bay coastal region and to provide sufficient geologic information for land-use and land-management decisions both onshore and offshore.
This information is not intended for navigational purposes.
Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
Although this Federal Geographic Data Committee-compliant metadata file is intended to document the data set in nonproprietary form, as well as in Esri format, this metadata file may include some Esri-specific terminology.
2007
2010
ground condition
As needed
-123.17
-122.97
38.41
38.25
USGS Metadata Identifier
USGS:879a6eb3-3551-46b3-9e54-552b5da7f0e5
Global Change Master Directory (GCMD)
Acoustic Reflectivity
ISO 19115 Topic Category
geoscientificInformation
environment
oceans
imageryBaseMapsEarthCover
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources
CMHRP
Pacific Coastal and Marine Science Center
PCMSC
Data Categories for Marine Planning
distributions
physical habitats and geomorphology
Marine Realms Information Bank (MRIB) keywords
seabed
sidescan sonar
marine geophysics
USGS Thesaurus
sidescan sonar
image mosaics
marine geophysics
sea-floor characteristics
sea-floor acoustic reflectivity
Coastal and Marine Ecological Classification Standard (CMECS)
Marine Nearshore Subtidal
Marine Offshore Subtidal
Transform Continental Margin
Continental/Island Shelf
Rock Substrate
Unconsolidated Mineral Substrate
Geographic Names Information System (GNIS)
Pacific Ocean
State of California
Bodega Bay
Sonoma County
Salmon Creek
Coastal and Marine Ecological Classification Standard (CMECS)
Northern California Ecoregion
Coastal and Marine Ecological Classification Standard (CMECS)
Substrate
none
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.
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060-5792
US
831-427-4747
pcmsc_data@usgs.gov
https://pubs.usgs.gov/ds/781/OffshoreBodegaHead/images/BackscatterB_7125_OffshoreBodegaHead.jpg
Acoustic backscatter imagery of the Offshore of Bodega Head map area.
JPEG
Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 10.0
Johnson, S.Y.
Dartnell, P.
Golden, N.E.
Hartwell, S.R.
Erdey, M.D.
Greene, H.G.
Cochrane, G.R.
Kvitek, R.G.
Manson, M.W.
Endris, C.A.
Dieter, B.E.
Watt, J.T.
Krisgman, L.M.
Sliter, R.W.
Lowe, E.N.
Chin, J.L.
2015
California State Waters Map Series--Offshore of Bodega Head, California
Open-File Report
2015-1140
Reston, VA
U.S. Geological Survey
https://doi.org/10.3133/ofr20151140
Not applicable for raster data.
Unspecified
Complete
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.
Not Applicable
During the Fugro Pelagos and CSUMB mapping missions, an Applanix Position and Motion Compensation System for Marine Vessels (POS/MV, 320, v4) was used to accurately position the vessels 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; heave accuracy, +/-5%, 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.
The multibeam backscatter data then were processed using Geocoder (Fugro Pelagos Modified Test Release 16) or Geocoder within Caris HIPS and SIPS. 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. This processed imagery was stored as Georeferenced, Backscatter Rasters (GeoBARs). After GeoBARs were created for each line, they were mosaicked into 1-m or 2-m resolution images. 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. The SWATHPlus backscatter data were processed using SXPTools v 2.0 (David Finlayson, USGS) and SEA Grid Processor v 3.02.19.0. SXPTools is a collection of command line programs that are used to enhance the quality of SEA SWATHplus interferometric sidescan sonar data. The programs are primarily focused on enhancing the backscatter quality, but there is some benefit to the bathymetry as well. The SXPTools sxpegn command was used to equalize the backscatter amplitude, and the sxpmagic command was used to help fill gaps and remove artifacts near nadir. After processing with SXPTools, lines were imported into Grid Processor and mosaicked into 1-m or 2-m resolution images. The mosaic image for each survey block was exported as a GeoJpeg from Grid Processor and converted to GeoTiff using Adobe Photoshop or GIMP. In some cases memory limitations in Grid Processor required tiling a block mosaic into 2 or more sub-mosaics.
2010
Carrie Bretz
Seafloor Mapping Lab, California State University Monterey Bay
Projects Manager, GIS; Metadata Supervisor
mailing and physical address
100 Campus Center, Bldg 13
Seaside
CA
93955
USA
(831) 582-4197
carrie_bretz@csumb.edu
California Seafloor Mapping Project 1- or 2-m resolution backscatter imagery 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. Grids were projected horizontally to WGS-84 using ESRI ArcTools.
2012
Pete Dartnell
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical address
2885 Mission St.
Santa Cruz
CA
95060-5792
USA
(831) 460-7415
pdartnell@usgs.gov
Added Distribution_Information section to metadata to facilitate data download.
20171005
U.S. Geological Survey
Alan O. Allwardt
Contractor -- Information Specialist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
831-460-7551
831-427-4748
aallwardt@usgs.gov
Keywords section of metadata optimized for discovery in USGS Coastal and Marine Geology Data Catalog.
20171005
U.S. Geological Survey
Alan O. Allwardt
Contractor -- Information Specialist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
831-460-7551
831-427-4748
aallwardt@usgs.gov
Added keywords from Coastal and Marine Ecological Classification Standard (CMECS) to metadata.
20180426
U.S. Geological Survey
Alan O. Allwardt
Contractor -- Information Specialist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060
831-460-7551
831-427-4748
aallwardt@usgs.gov
Edited metadata to add keywords section with USGS persistent identifier as theme keyword. No data were changed.
20201019
U.S. Geological Survey
VeeAnn A. Cross
Marine Geologist
Mailing and Physical
384 Woods Hole Road
Woods Hole
MA
02543-1598
508-548-8700 x2251
508-457-2310
vatnipp@usgs.gov
Edited metadata to fix validation errors and to bring it up to FGDC CSDGM current standards based on data release policies for USGS Coastal and Marine Hazards and Resources Program (CMHRP). No data were changed. The metadata available from a harvester may supersede metadata bundled within a download file. Users are advised to compare the metadata dates to determine which metadata file is most recent.
20220722
U.S. Geological Survey
Susan Cochran
Geologist
Mailing and Physical
2885 Mission Street
Santa Cruz
CA
95060
831-460-7545
scochran@usgs.gov
Raster
Grid Cell
Universal Transverse Mercator
10
0.9996
-123.00000
0.00000
500000.0
0.00
coordinate pair
2.0
2.0
Meters
WGS84
WGS84
6378137.00
298.257223563
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 = 8861
>Number of columns = 8866
>
>Data type = unsigned integer
>
>Boundary
>Xmin = 484919
>Xmax = 502651
>Ymin = 4233779
>Ymax = 4251501
>
>Statistics
>Minimum value = 0
>Maximum value = 254
>Mean = 96.66
>Standard deviation = 20.53
>
>Coordinate system description
>Projection UTM
>Zone 10
>Datum WGS84
>Units meter
none
U.S. Geological Survey
mailing and physical address
345 Middlefield Rd
Menlo Park
CA
94025-3561
USA
(650) 329-4309
The .zip file (https://pubs.usgs.gov/ds/781/OffshoreBodegaHead/data/BackscatterB_7125_OffshoreBodegaHead.zip) includes the .tfw, .tif, .tif.aux.xml, and .tif.ovr, files, as well as FGDC-compliant metadata for the BackscatterB_7125 data layer in the Bodega Head region of California.
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.
GeoTiff
ArcMap (version 10.0, ESRI, 2011)
Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system.
The .zip file for the TIFF image includes the image (.tif), the world registration file (.tfw), and FGDC-compliant metadata.
WinZip
1.5
https://pubs.usgs.gov/ds/781/OffshoreBodegaHead/data/BackscatterB_7125_OffshoreBodegaHead.zip
https://pubs.usgs.gov/ds/781/OffshoreBodegaHead/data_catalog_OffshoreBodegaHead.html
https://doi.org/10.3133/ds781
The first link will begin a direct download of the data. The second link is a landing page on which all of the downloadable data for a particular region are listed. The third link is a landing page for the entire data catalog.
none
20220722
U.S. Geological Survey, Pacific Coastal and Marine Science Center
PCMSC Science Data Coordinator
mailing and physical
2885 Mission Street
Santa Cruz
CA
95060-5792
US
831-427-4747
pcmsc_data@usgs.gov
Content Standard for Digital Geospatial Metadata
FGDC-STD-001-1998
local time