Open-File Report 02-162
Data
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This Open-File Report contains the bathymetry and acoustic backscatter data for the three Los Angeles Margin multibeam surveys (see location map). The data are provided in two formats (ASCII XYZ and ESRI's ArcInfo GRID) that can be used in a number of GIS and other software packages. The bathymetry data from the three surveys have been merged into a common grid and is published at 16-m spatial resolution. The acoustic backscatter data from the three surveys are published as separate files. Each survey used a different multibeam system that operated at a different frequency. This results in an inconsistent acoustic backscatter intensity between surveys due to depth of acoustic penetration, resolution, etc.
BATHYMETRY DATA The bathymetry data are available in ASCII XYZ (x-coordinate, y-coordinate, depth) and ArcInfo GRID. The data are available in comma delimited XYZ (x-coordinate, y-coordinate, value) format. Instructions 1. Download the file (see below) to the desktop. 2. Uncompress the files. The files are compressed with WinZip 7.0. 3. The uncompression will result in a new comma delimited file (bathy.csv). Disclaimer: Downloading files can sometimes be problematic. Different web browsers and operating systems act differently. The instructions above may vary from system to system or may not work at all.
Projection Information The data are also available in ArcInfo GRID format that can be used directly in ESRI ArcInfo, ArcView, or any other GIS or remote sensing software package that supports ESRI GRID format. In ArcView, the GRID files will be most useful with the Spatial Analyst Extension. Download GRIDS to desktop 1. Download the file (see below) to the desktop. 2. Uncompress and unbundle the file. Since ESRI GRIDs are directories of files, the directory has been bundled into a single file and then compressed for downloading. Windows - Double click on the file (bathy.tgz). Winzip 7.0 will uncompress the file resulting in a new bundled file (bathy.tar). Double click on the new file and Winzip 7.0 will unbundle the file into a new folder (bathy). The ESRI GRID (bathyg) is contained within the folder. UNIX - Uncompress using "gunzip" then unbundle using "tar xf". 3. The bathymetry GRID file (bathyg) is contained within the folder (bathy). Disclaimer: Downloading files can sometimes be problematic. Different web browsers and operating systems act differently. The instructions above may vary from system to system or may not work at all. One possible problem when downloading the file using Netscape the *.tgz extension automatically changes to *.tar and the file does not uncompress correctly. If this is the case change the *.tar back to *.tgz and uncompress as normal.
Projection Information ACOUSTIC BACKSCATTER DATA The acoustic backscatter data from the three Los Angeles Margin multibeam surveys are published as three separate files (Santa Monica Bay, Newport, and Long Beach Shelf, see location map). Each survey used a different multibeam system that operated at a different frequency. This results in an inconsistent acoustic backscatter intensity between surveys due to depth of penetration, resolution, etc. Each survey's acoustic backscatter data are published inASCII XYZ and ESRI ArcInfo GRID format The backscatter data are available in comma delimited XYZ (x-coordinate, y-coordinate, value) format. Instructions 1. Download the files (see below) to the desktop. 2. Uncompress the files. The files are compressed with WinZip 7.0. 3. The uncompression will result in a new comma delimited file (smmos.csv). Disclaimer: Downloading files can sometimes be problematic. Different web browsers and operating systems act differently. The instructions above may vary from system to system or may not work at all.
Projection Information The data are also available in ArcInfo GRID format that can be used directly in ESRI ArcInfo, ArcView, or any other GIS or remote sensing software package that supports ESRI GRID format. In ArcView, the GRID files will be most useful with the Spatial Analyst Extension. Download GRIDS to desktop 1. Download the files (see below) to the desktop. 2. Uncompress and unbundle the files. Since ESRI GRIDs are directories of files, the directories have been bundled into a single file and then compressed for downloading. Windows - Double click on the file (*.tgz). Winzip 7.0 will uncompress the file resulting in a new bundled file (*.tar). Double click on the new file and Winzip 7.0 will unbundle the file into a new folder (*mos). The ESRI GRID (*mosg) is contained within the folder. UNIX - Uncompress using "gunzip" then unbundle using "tar xf". 3. The backscatter GRID file (*mosg) is contained within the folder (*mos). Disclaimer: Downloading files can sometimes be problematic. Different web browsers and operating systems act differently. The instructions above may vary from system to system or may not work at all. One possible problem when downloading the file using Netscape the *.tgz extension automatically changes to *.tar and the file does not uncompress correctly. If this is the case change the *.tar back to *.tgz and uncompress as normal.
Projection Information |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://pubsdata.usgs.gov/pubs/of/2002/0162/data.html
Page Contact Information: GS Pubs Web Contact
Page Last Modified: Wednesday, 07-Dec-2016 19:26:19 EST
