Peter Dartnell
Mercedes D. Erdey
Rikk G. Kvitek
Carrie Bretz
2014
Backscatter B [8101]--Offshore Bolinas, California
1.0
GeoTiff
Guy R. Cochrane
Peter Dartnell
Samuel Y. Johnson
H. Gary Greene
Mercedes D. Erdey
Nadine E. Golden
Stephen R. Hartwell
Michael W. Mansion
Ray W. Sliter
Charles A. Endris
Janet T. Watt
Stephanie L. Ross
Rikk G. Kvitek
Eleyne L. Phillips
Terry R. Bruns
John L. Chin
2015
California State Waters Map Series--Offshore of Bolinas Map Area, California
map
Open-File Report
OFR 2015-1135
Reston, VA
U.S. Geological Survey
https://dx.doi.org/10.3133/ofr20151135
https://pubs.usgs.gov/of/2015/1135/
Nadine E. Golden
2013
California State Waters Map Series Data Catalog
database
Data Series
DS 781
Reston, VA
U.S. Geological Survey
https://pubs.usgs.gov/ds/781/
https://www.sciencebase.gov/arcgis/rest/services/Catalog/5556cd65e4b0a92fa7e9cfbd/MapServer
https://www.sciencebase.gov/arcgis/services/Catalog/5556cd65e4b0a92fa7e9cfbd/MapServer/WMSServer?request=GetCapabilities&service=WMS
This part of DS 781 presents data for the acoustic-backscatter map of the Offshore of Bolinas map area, California. Backscatter data are provided as separate grids depending on mapping system or processing method. The raster data files is included in "BackscatterB_8101_2007_OffshoreBolinas.zip", which are accessible from https://pubs.usgs.gov/ds/781/OffshoreBolinas/data_catalog_OffshoreBolinas.html.
The acoustic-backscatter map of the Offshore of Bolinas map area, California, was generated from backscatter collected by California State University, Monterey Bay (CSUMB), by Fugro Pelagos, and by Moss Landing Marine Laboratory (MLML). Mapping was completed between 2004 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 and 250-kHz GeoSwath interferometric systems. Moss Landing Marine Laboratory mapped the nearshore region north of Bolinas in 2004 prior to the California Seafloor Mapping Program (CSMP). The nearshore region from south of Bolinas Lagoon to Stinson Beach was mapped by Fugro Pelagos in 2009 for a project outside of the CSMP and only bathymetry data were collected. Therefore, note that the shaded relief map coverage (see Bathymetry Hillshade--Offshore of Bolinas, California, DS 781) does not match the acoustic-backscatter map coverage (see Backscatter A-E--Offshore of Bolinas, California, DS 781). 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). These data are not intended for navigational purposes.
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 seafloor features.
None
2004
2010
ground condition
As needed
-122.78
-122.58
37.97
37.81
Global Change Master Directory (GCMD)
Oceans > Bathymetry/SeafloorTopography > Bathymetry
Oceans > Bathymetry/SeafloorTopography > Seafloor Topography
ISO 19115 Topic Category
geoscientificInformation
environment
oceans
imageryBaseMapsEarthCover
Geographic Names Information System (GNIS)
Pacific Ocean
State of California
Bolinas
Marin County
Stinson Beach
Bolinas Lagoon
If physical samples or materials are available, constraints on their on-site access are described in "WR CMG Sample Distribution Policy"
at URL: https://walrus.wr.usgs.gov/infobank/programs/html/main/sample-dist-policy.html
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.
Peter Dartnell
U.S. Geological Survey,
Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical address
400 Natural Bridges Dr.
Santa Cruz
CA
95060-5792
USA
(831) 460-7415
(831) 427-4709
pdartnell@usgs.gov
<https://pubs.usgs.gov/ds/781/OffshoreBolinas/images/BackscatterB_8101_2007_OffshoreBolinas.jpg>
Acoustic backscatter imagery of offshore Bolinas.
JPEG
Not applicable for raster data.
Unspecified
Complete
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 to acoustic-backscatter imagery.
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 vesselsí 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. Backscatter data then were processed using the CARIS integration of Geocoder. 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 1m 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.
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
USGS received original Caris HIPS and SIPS projects from CSUMB of the 2004-2005 multibeam survey of the Entrance to San Francisco Bay. USGS re-processed the backscatter data using Caris (version 7.1) integration of Geocoder. 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 1m 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.
2011
Mercedes Erdey
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical address
400 Natural Bridges Dr.
Santa Cruz
CA
95060-5792
USA
(831) 460-????
merdey@usgs.gov
California Seafloor Mapping Project 1- and 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.
2012
Pete Dartnell
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical address
400 Natural Bridges Dr.
Santa Cruz
CA
95060-5792
USA
(831) 460-7415
pdartnell@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 meters
298.257223563
The USGS re-processed Entrance to San Francisco Bay (CSUMB) acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:
>Cell size = 2.0
>Number of rows = 8846
>Number of columns = 8846
>
>Data type = unsigned integer
>
>Boundary
>Xmin = 518936
>Xmax = 536628
>Ymin = 4184863
>Ymax = 4202555
>
>Statistics
>Minimum value = 0
>Maximum value = 254
>Mean = 183.33
>Standard deviation = 27.12
>
>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 = 8846
>Number of columns = 8846
>
>Data type = unsigned integer
>
>Boundary
>Xmin = 518936
>Xmax = 536628
>Ymin = 4184863
>Ymax = 4202555
>
>Statistics
>Minimum value = 39
>Maximum value = 254
>Mean = 122.56
>Standard deviation = 35.24
>
>Coordinate system description
>Projection UTM
>Zone 10
>Datum WGS84
>Units meter
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 = 3822
>Number of columns = 3737
>
>Data type = unsigned integer
>
>Boundary
>Xmin = 518439
>Xmax = 525913
>Ymin = 4192448
>Ymax = 4200092
>
>Statistics
>Minimum value = 2
>Maximum value = 251
>Mean = 94.53
>Standard deviation = 18.73
>
>Coordinate system description
>Projection UTM
>Zone 10
>Datum WGS84
>Units meter
The merged Reson Snippets acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:
>Cell size = 2.0
>Number of rows = 8846
>Number of columns = 8846
>
>Data type = unsigned integer
>
>Boundary
>Xmin = 518936
>Xmax = 536628
>Ymin = 4184863
>Ymax = 4202555
>
>Statistics
>Minimum value = 1
>Maximum value = 254
>Mean = 137.67
>Standard deviation = 29.34
>
>Coordinate system description
>Projection UTM
>Zone 10
>Datum WGS84
>Units meter
The merged Swath acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:
>Cell size = 2.0
>Number of rows = 8846
>Number of columns = 8846
>
>Data type = unsigned integer
>
>Boundary
>Xmin = 518936
>Xmax = 536628
>Ymin = 4184863
>Ymax = 4202555
>
>Statistics
>Minimum value = 1
>Maximum value = 254
>Mean = 117.46
>Standard deviation = 33.13
>
>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
These databases, identified as bathymetry and shaded-relief maps of Offshore Bolinas map area, California have been approved for release and publication by the U.S. Geological Survey (USGS). Although these databases have been subjected to rigorous review and are 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 these data have been processed successfully on a computer system at 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 USGS or the U.S. Government shall not be held liable for improper or incorrect use of the data described and/or contained herein.
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.
These data are not intended for navigational use.
TIFF
ArcMap (version 10.0, ESRI , 2011)
Raster data layer is registered TIFF image in the UTM Zone 10 coordinate system with datum WGS84.
The .zip file for the TIFF image includes the image (.tif), the world registration file (.tfw), and the text (.txt) and XML (.tif.xml) versions of the metadata for the BackscatterB [8101] 2007 data layer of Offshore Bolinas, California.
WinZip
0.5
https://pubs.usgs.gov/ds/781/OffshoreBolinas/data/BackscatterB_8101_2007_OffshoreBolinas.zip
https://pubs.usgs.gov/ds/781/
Data can be downloaded via the World Wide Web (WWW)
none
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, OffshoreBolinasGIS.mxd.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 "Offshore Bolinas" and has all the data symbolized as on the OFR map sheets. Download and save this ArcGIS project file, including all data layers, to the directory the user has created for this GIS.
20140218
20140904
Peter Dartnell
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical address
400 Natural Bridges Dr.
Santa Cruz
CA
95060-5792
USA
(831) 460-7415
(831) 427-4709
pdartnell@usgs.gov
Content Standard for Digital Geospatial Metadata
("CSDGM version 2")
FGDC-STD-001-1998
universal time