Peter Dartnell
Andrew C. Ritchie
David P. Finlayson
2015
BackscatterB [EM300]--Offshore Aptos, California
1.0
GeoTiff
Data Series
DS 781
Reston, VA
U.S. Geological Survey
https://doi.org/10.3133/ds781
https://cmgds.marine.usgs.gov/data/csmp/OffshoreAptos/data_catalog_OffshoreAptos.html
Nadine E. Golden
2015
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 Offshore of Aptos map area, California. Backscatter data are provided as two separate grids depending on mapping system and processing method. This metadata file refers to the data included in "BackscatterB_EM300_OffshoreAptos.zip," which is accessible from https://doi.org/10.5066/F7K35RQB. These data accompany the pamphlet and map sheets of Cochrane, G.R., Johnson, S.Y., Dartnell, P., Greene, H.G., Erdey, M.D, Dieter, B.E., Golden, N.E., Hartwell, S.R., Ritchie, A.C., Kvitek, r.G., Maier, K.L., Endris, C.A., Davenport, C.W., Watt, J.T., Sliter, R.W., Finlayson, D.P., and Krigsman, L.M., (G.R. Cochrane and S.A. Cochran, eds.), 2016, California State Waters Map Series—Offshore of Aptos, California: U.S. Geological Survey Open-File Report 2016–1025, 43 p., 10 sheets, scale 1:24,000, https://doi.org/10.3133/ofr20161025.
The acoustic-backscatter map of Offshore of Aptos, California was generated from backscatter data collected by the U.S. Geological Survey (USGS) and by Monterey Bay Aquarium Research Institute (MBARI). Mapping was completed between 1998 and 2009, using a combination of a 234-kHz SWATHplus bathymetric sidescan-sonar system and a 30-kHz Simrad EM-300 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 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 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.
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.
1998
2009
ground condition
none planned
-122.00
-121.80
37.00
36.84
USGS Metadata Identifier
USGS:556f768ce4b0d9246a9fd058
Global Change Master Directory (GCMD)
Acoustic Reflectivity
None
U.S. Geological Survey
USGS
Coastal and Marine Hazards and Resources Program
CMHRP
Pacific Coastal and Marine Science Center
PCMSC
Fisheries
Backscatter
Intensity
ISO 19115 Topic Category
geoscientificInformation
environment
oceans
imageryBaseMapsEarthCover
Data Categories for Marine Planning
distributions
physical habitats and geomorphology
Marine Realms Information Bank (MRIB) keywords
seabed
sidescan sonar
marine geophysics
USGS Thesaurus
Geology
Bathymetry
ecosystems
multibeam sonar
sonar methods
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
Aptos
Santa Cruz County
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://www.sciencebase.gov/catalog/file/get/5576269de4b032353caef2b1?f=__disk__b8%2Fb7%2F78%2Fb8b778256890d471466bd6bebdef342ebb30be7b&allowOpen=true
Acoustic backscatter imagery offshore of Aptos, California
JPEG
Microsoft Windows Server 2008 R2 Version 6.1 (Build 7601) Service Pack 1; ESRI ArcCatalog 10.0
Guy R. Cochrane
Samuel Y. Johnson
Peter Dartnell
H. Gary Greene
Mercedes D. Erdey
Bryan E. Dieter
Nadine E. Golden
Stephen R. Hartwell
Andrew C. Ritchie
Rikk G. Kvitek
Katherine L. Maier
Charles A. Endris
Clifton W. Davenport
Janet T. Watt
Ray W. Sliter
David P. Finlayson
Lisa M. Krigsman
2016
California State Waters Map Series--Offshore of Aptos, California
map
Open-File Report
2016-1025
Reston, VA
U.S. Geological Survey
https://doi.org/10.3133/ofr20161025
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 MBARI mapping mission an Applied Analytic POS MV (Position and Orientation System for Marine Vessels) was used to accurately position the vessel and account for vessel motion with navigational input from a kinematic GPS system. Soundings were corrected for variations in water-column sound velocity using data from a SeaBird CTD and Sippican T5 expendable bathythermographs. The MBARI EM-300 backscatter data covering the head of Soquel Submarine Canyon were used in the Offshore of Aptos map. The USGS downloaded the original MBARI survey line files from the National Geophysical Data Center (NGDC) on-line bathymetry server (http://www.ngdc.noaa.gov/mgg/bathymetry/relief.html). Using MB-Systems, amplitude values were extracted from the survey line files and exported as one overall XYZ file. The XYZ file was gridded at 5-m spatial resolution in Fledermaus software (QPS), converted to an ASCIIRaster file, and imported into a geographic information system (GIS). The grid was clipped to the offshore of Aptos map boundary.
2014
Pete Dartnell
U.S. Geological Survey, Pacific Coastal and Marine Science Center
Physical Scientist
mailing and physical address
2885 Mission Street
Santa Cruz
CA
95060-5792
USA
(831) 460-7415
pdartnell@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
Edits were made to bring the metadata up to current PCMSC standards including standardizing authors' names, adding a doi# link, correcting typos, refining keywords, and using current access and distribution liability statements. Point of Contact and Metadata Contact information sections were changed to static PCMSC contact information. No data were changed. Users are advised to compare the metadata date of this file to any similar file to ensure they are using the most recent version.
20200908
Susan A Cochran
U.S. Geological Survey, Pacific Coastal and Marine Science Center
mailing and physical
2885 Mission St.
Santa Cruz
CA
95060
United States
831-460-7545
scochran@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
Raster
Grid Cell
3522
3566
1
Universal Transverse Mercator
10
0.9996
-123.00000
0.00000
500000.0
0.00
coordinate pair
5.0
5.0
Meters
WGS84
WGS84
6378137.00
298.257223563
Value
BackscatterB [EM300] intensity value
ESRI
VALUE
Backscatter intensity values
ESRI
-55
-8
Floating point values representing intensity
The EM-300 acoustic-backscatter grid was originally archived as an ESRI grid with the following attributes:
>Cell size = 5.0
>Number of rows = 3522
>Number of columns = 3566
>
>Data type = floating point
>
>Boundary
>Xmin = 588830
>Xmax = 606660
>Ymin = 4077950
>Ymax = 4095560
>
>Statistics
>Minimum value = -55
>Maximum value = -8
>Mean = -35.91
>Standard deviation = 2.39
>
>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 download includes the image (.tif), the world registration file (.tfw), tif.ovr, and a color ramp file. The text (.txt), XML (.tif.xml), HTML, and FAQ versions of the metadata for the BackscatterB [EM300] data layer of Offshore Aptos, California are also included in the download.
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 with datum WGS84.
The .zip file for the TIFF image includes the image (.tif), the world registration file (.tfw), .ovr and a color ramp file. The text (.txt), XML (.tif.xml), HTML, and FAQ versions of the metadata for the BackscatterB [EM300] data layer of Offshore Aptos, California are also included in the download.
WinZip
0.48
https://www.sciencebase.gov/catalog/file/get/556f768ce4b0d9246a9fd058
https://www.sciencebase.gov/catalog/item/556f7222e4b0d9246a9fd04e
https://pubs.usgs.gov/ds/781/
Data can be downloaded using the Network Resource links. 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
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, OffshoreAptosGIS.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 Aptos" 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.
20201019
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