United States Geological Survey (USGS),
Coastal and Marine Geology (CMG),
Chief Scientist (Peter Dartnell)
2004
Multibeam Backscatter of the Los Angeles, California Margin
ESRI ArcInfo GRID
ESRI ArcInfo GRID format data generated from the 1996, 1998, and 1999
multibeam sonar surveys of the Los Angeles, California Margin.
The data include high-resolution corrected acoustic backscatter. Disclaimer: These datasets in their present form were not originally intended for publication. The bathymetry and backscatter are full of data-collection and processing artifacts. Outside influences beyond our control required us to publish these datasets in their present form. Care must be taken not to confuse artifacts with real seafloor morphology and acoustic backscatter.
These data are intended for science researchers,
students, policy makers, and the general public.
The data can be used with geographic information systems (GIS)
or other software to display acoustic backscatter data
of the Los Angeles, California Margin.
Information for USGS Coastal and Marine Geology related
activities are online at
<http://walrus.wr.usgs.gov/infobank/c/c196sc/html/c-1-96-sc.meta.html>
<http://walrus.wr.usgs.gov/infobank/a/a398sc/html/a-3-98-sc.meta.html>
<http://walrus.wr.usgs.gov/infobank/c/c199sc/html/c-1-99-sc.meta.html>
19960930
19990518
ground condition
As needed
-118.850
-117.754
34.029
33.334
GCMD DIF, Version 5.0a, September 1996: Parameter Keywords
Earth Science > Oceans > Bathymetry/Seafloor Topography > Bathymetry
Earth Science > Oceans > Bathymetry/Seafloor Topography > Seafloor Topography
Earth Science > Oceans > Bathymetry/Seafloor Topography > Water Depth
None
Marine Geology
Multibeam
Acoustic Backscatter
Backscatter
None
Los Angeles Margin
CA
Southern California
USA
None
Please recognize the U.S. Geological Survey (USGS)
as the source of this information.
USGS-authored or produced data and information
are in the public domain.
Peter Dartnell
United States Geological Survey (USGS)
Coastal and Marine Geology (CMG)
Physical Scientist
mailing and physical address
USGS, MailStop 999, 345 Middlefield Road
Menlo Park
CA
94025-3561
USA
(650) 329-5460
(650) 329-5411
pdartnell@usgs.gov
Not applicable for raster data.
Unspecified
Complete
0.5 meters
0.05 percent of the water depth. Depths corrected to mean lower low water datum.
The multibeam bathymetry and acoustic backscatter data were collected
along a continuous swath perpendicular to the direction
of the ship using a Kongsberg Simrad EM1000 multibeam sonar system.
The data are cleaned of bad navigation and depth readings and corrected for tides to mean lower low water datum.
The acoustic backscatter readings are gridded into a common grid.
The gridded data are converted to ArcInfo GRID format
using ArcInfo's ASCIIGRID command.
19961030
Peter Dartnell
United States Geological Survey (USGS)
Coastal and Marine Geology (CMG)
Peter Dartnell
mailing and physical address
USGS, MailStop 999, 345 Middlefield Road
Menlo Park
CA
94025-3561
USA
(650) 329-5460
(650) 329-5411
pdartnell@usgs.gov
Raster
Grid Cell
Universal Transverse Mercator
11
0.9996
-117.00000
0.00000
0.00
0.00
coordinate pair
2.0, 4.0, 8.0
2.0, 4.0, 8.0
Meters
WGS84
WGS84
6378137.00 meters
0.003352811
dumemosg is an ESRI ArcInfo GRID with the following attributes (example):
Cell Size = 2.000
Data Type: Floating Point
Number of Rows = 1020
Number of Columns = 6310
BOUNDARY
Xmin = 332279.651
Xmax = 344899.651
Ymin = 3762484.488
Ymax = 3764524.488
STATISTICS
Minimum Value = 47.001
Maximum Value = 250.000
Mean = 188.934
Standard Deviation = 6.718
none
United States Geological Survey (USGS)
Information Services
mailing and physical address
345 Middlefield Rd., MS-999
Menlo Park
CA
94025
USA
(650)329-5460
C-1-96-SC, A-3-98-SC, and C-1-99-SC data sets
These data not intended for navigational purposes.
Although these data have been used by the
U.S. Geological Survey, U.S. Department of the Interior,
these data and information are provided
with the understanding that they are not guaranteed
to be usable, timely, accurate, or complete.
Users are cautioned to consider carefully
the provisional nature of these data and information
before using them for decisions that concern personal or
public safety or the conduct of business that involves
substantial monetary or operational consequences.
Conclusions drawn from, or actions undertaken
on the basis of, such data and information are
the sole responsibility of the user.
Neither the U.S. Government nor any agency thereof,
nor any of their employees, contractors, or subcontractors,
make any warranty, express or implied,
nor assume any legal liability or responsibility
for the accuracy, completeness, or usefulness
of any data, software, information, apparatus, product, or
process disclosed, nor represent that its use
would not infringe on privately owned rights.
Trade, firm, or product names and other references
to non-USGS products and services are provided
for information only and do not constitute
endorsement or warranty, express or implied,
by the USGS, USDOI, or U.S. Government,
as to their suitability, content, usefulness,
functioning, completeness, or accuracy.
ArcInfo GRID
8.0.2
none
None
20040412
Peter Dartnell
United States Geological Survey (USGS)
Coastal and Marine Geology (CMG)
Physical Scientist
mailing and physical address
USGS, MailStop 999, 345 Middlefield Road
Menlo Park
CA
94025-3561
USA
(650) 329-5460
(650) 329-5411
pdartnell@usgs.gov
Content Standard for Digital Geospatial Metadata
("CSDGM version 2")
FGDC-STD-001-1998
universal time