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Backscatter A: Hueneme Canyon and Vicinity, California, 2008

Identification Information

Citation
Title
Backscatter A: Hueneme Canyon and Vicinity, California, 2008
Originator
Phillips, Eleyne L.
Originator
Ritchie, Andrew C.
Originator
Kvitek, Rikk G.
Originator
Johnson, Samuel Y.
Originator
Dartnell, Peter
Originator
Pacific Coastal and Marine Science Center
Originator
Golden, Nadine E.
Publisher
Geological Survey (U.S.)
Place of Publication
Santa Cruz , California , US
Publication Date
2012-01-01
Edition
1.0
Identifier
http://purl.stanford.edu/hm490xd8335
Geospatial Data Presentation Form
mapDigital
Collection Title
California State Waters Map Series (USGS Data Series 781)
Other Citation Details
These data were downloaded from http://pubs.usgs.gov/ds/781 on July 15, 2015
Series
Series Title
USGS Data Series
Issue
781
Abstract
This layer is a georeferenced raster image containing acoustic-backscatter data for Hueneme Canyon and the surrounding vicinity in California. The majority of the data for this map area was collected by CSUMB in the summers of 2006 and 2007, using a 244-kHz Reson 8101 multibeam echosounder. 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 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). This map was published in Scientific Investigations Map 3225. This layer is part of the USGS Data Series 781.
Purpose
In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP) to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats and geology within the 3-nautical-mile limit of California's State Waters. CSMP has divided coastal California into 110 map blocks, each to be published individually as United States Geological Survey Open-File Reports (OFRs) or Scientific Investigations Maps (SIMs) at a scale of 1:24,000. Maps display seafloor morphology and character, identify potential marine benthic habitats and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. Data layers for bathymetry, bathymetric contours, acoustic backscatter, seafloor character, potential benthic habitat and offshore geology were created for each map block, as well as regional-scale data layers for sediment thickness, depth to transition, transgressive contours, isopachs, predicted distributions of benthic macro-invertebrates and visual observations of benthic habitat from video cruises over the entire state. These data are intended for science researchers, students, policy makers, and the general public. This information is not intended for navigational purposes.The data can be used with geographic information systems (GIS) software to display geologic and oceanographic information.
Temporal Extent
Currentness Reference
ground condition
Time Period
Begin
2006-01-01T00:00:00
End
2008-12-31T00:00:00
Bounding Box
West
-119.338007
East
-119.139569
North
34.223097
South
34.058099
Bounding Box
West
-119.338007
East
-119.139569
North
34.223097
South
34.058099
ISO Topic Category
imageryBaseMapsEarthCover
oceans
elevation
Place Keyword
California
Ventura County (Calif.)
Pacific Ocean
Place Keyword Thesaurus
geonames
Temporal Keyword
2006-2008
Theme Keyword
Coasts
Digital elevation models
Remote sensing
Bathymetric maps
Multibeam mapping
Submarine topography
Submarine geology
Sediments (Geology)
Marine sediments
Ocean bottom
Seismic reflection method
Theme Keyword Thesaurus
lcsh
Legal Constraints
Other Restrictions
This item is in the public domain. There are no restrictions on access or use.
Status
completed
Maintenance and Update Frequency
asNeeded
Collection
Collection Title
California State Waters Map Series (USGS Data Series 781)
URL
http://purl.stanford.edu/ng324gh5570
Publication Date
2013-01-01
Language
eng
Credit
U.S. Geological Survey. (2013). Backscatter A: Hueneme Canyon and Vicinity, California, 2008. California State Waters Map Series Data Catalog: U.S. Geological Survey Data Series 781. Available at: http://purl.stanford.edu/hm490xd8335.
Point of Contact
Contact
Dartnell, Peter
Position Name
Physical Scientist
Delivery Point
400 Natural Bridges Dr.
City
Santa Cruz
Administrative Area
CA
Postal Code
95060
Country
US
Email
PDartnell@usgs.gov
Phone
(831) 460-7415

Spatial Reference Information

Reference System Identifier
Code
32611
Code Space
EPSG
Version
2.1(3.0.1)

Data Quality Information

Quantitative Attribute Accuracy Report
Absolute External Positional Accuracy
Absolute External Positional Accuracy
Lineage
Process Step
Description
CSUMB acoustic-backscatter data were collected in the summers of 2006 and 2007, using a 244-kHz Reson 8101 multibeam echosounder. During the CSUMB mapping missions, an Applanix positioning 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 degrees; heave accuracy, +/-5 percent, or 5 cm). NavCom 2050 GPS receiver (CNAV) data were used to account for tidal-cycle fluctuations, and sound-velocity profiles were collected with an Applied Microsystems (AM) 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 CNAV receiver.
Process Date
2007-01-01T00:00:00
Process Step
Description
USGS received original Caris HIPS/SIPS projects from CSUMB for CSUMB survey blocks A-H. Backscatter data were postprocessed by the USGS using CARIS7.0/Geocoder software. Geobars were created for each survey line using the beam-averaging engine. Intensities were radiometrically corrected (including despeckling and angle-varying gain adjustments), and the position of each acoustic sample was geometrically corrected for slant range on a line-by-line basis. The contrast and brightness of some geobars were adjusted to better match the surrounding geobars. Individual geobars were mosaicked together at 2-m resolution using the auto-seam method. The mosaics were then exported from CARIS as georeferenced TIFF images, imported into a GIS, and converted to GRIDS and clipped to the Hueneme Canyon and vicinity, California, map boundary.
Process Date
2009-01-01T00:00:00

Distribution Information

Format Name
Raster Dataset
Distributor
Stanford Geospatial Center
Online Access
http://purl.stanford.edu/hm490xd8335
Protocol
http
Name
BackscatterA_HuenemeCanyon.tif
Function
download

Content Information

Content Type
image

Spatial Representation Information

Raster
Number of Dimensions
2
Column Count
8958
Row Count
8958
Cell Geometry Type
area
Corner Points
Point
284625.000000 3771055.000000
Point
284625.000000 3788971.000000
Point
302541.000000 3788971.000000
Point
302541.000000 3771055.000000
Center Point
293583.000000 3780013.000000

Metadata Reference Information

Hierarchy Level
dataset
Metadata File Identifier
edu.stanford.purl:hm490xd8335
Parent Identifier
http://purl.stanford.edu/ng324gh5570.mods
Dataset URI
http://purl.stanford.edu/hm490xd8335
Metadata Date Stamp
2017-11-21
Metadata Standard Name
ISO 19139 Geographic Information - Metadata - Implementation Specification
Metadata Standard Version
2007
Character Set
utf8
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