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OAS accession Detail for 0001410, meta_version: 3. Current meta_version is: 6
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| accessions_id: | 0001410 | archive |
|---|---|
| Title: | Bathymetric Survey of the West Florida Shelf, Gulf of Mexico 2001 (NODC Accession 0001410) |
| Abstract: | A zone of deep-water reefs is thought to extend from the mid and outer shelf south of Mississippi and Alabama to at least the northwestern Florida shelf off Panama City, Florida. Reefs off Mississippi and Alabama are found in water depths of 60 to 120 m (Ludwick and Walton, 1957, Gardner et al., in press) and were the focus of a multibeam echosounder (MBES) mapping survey by the U.S. Geological Survey (USGS) in 2000 (Gardner et al., 2000, in press). It is critical to determine the accurate geomorphology and type of the reefs that occur because of their importance as benthic habitats for fisheries. These data are ArcInfo GRID and XYZ ASCII format data generated from a U.S. Geological Survey multibeam sonar survey of the West Florida Shelf, Gulf of Mexico. The data include high-resolution bathymetry and calibrated acoustic backscatter. File types include arc files .dat, .nit, and .adf. Documentation is included as metadata .txt files. |
| Date received: | 20040401 |
| Start date: | 20010903 |
| End date: | 20011012 |
| Seanames: | Gulf of Mexico |
| West boundary: | -86.71 |
| East boundary: | -84.61 |
| North boundary: | 30.06 |
| South boundary: | 28.04 |
| Observation types: | physical |
| Instrument types: | multibeam sonar |
| Datatypes: | BATHYMETRY |
| Submitter: | Gardner, James V. |
| Submitting institution: | US DOI; USGS; Western Region |
| Collecting institutions: | US DOI; USGS; Western Region |
| Contributing projects: | CORAL REEF STUDIES, CoRIS |
| Platforms: | |
| Number of observations: | 8 |
| Supplementary information: | Additional online information: Multibeam Mapping of the West Florida Shelf, Gulf of Mexico (http://geopubs.wr.usgs.gov/open-file/of02-005/) Cruise report (http://geopubs.wr.usgs.gov/open-file/of01-448/) Multibeam sonar = instrument 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 bathymetry and backscatter data of the West Florida Shelf, Gulf of Mexico. More information on these data formats: "Arc/Info Binary Grid Format by Frank Warmerdam (warmerdam@pobox.com)- FYI downloaded June 2009 at NODC The Arc/Info Binary Grid format is the internal working format of the Arc/Info Grid product. It is also usable and creatable within the spatial analyst component of ArcView. It is a tiled (blocked) format with run length compression capable of holding raster data of up to 4 byte integers or 4 byte floating data. This format should not be confused with the Arc/Info ASCII Grid format which is the interchange format for grids. Files can be converted between binary and ASCII format with the GRIDASCII and ASCIIGRID commands in Arc/Info. This format is also different than the flat binary raster output of the GRIDFLOAT command. The Arc/Info binary float, and ASCII formats are also accessable from within ArcView. This format should also not be confused with what I know as ESRI BIL format. This is really a standard ESRI way of creating a header file (.HDR) describing the data layout a binary raster file containing raster data. Version I am not sure yet how the versions work for grid files. I have been working primarily with grid files generated by ArcView 3.x, and it's associated gridio API. The hdr.adf files I have examined start with the string GRID1.2 for what that's worth. Certainly the file naming conventions seem to follow the Arc/Info 7.x conventions rather than that of earlier versions. File Set A grid coverage actually consists of a number of files. A grid normally lives in it's own directory named after the grid. For instance, the grid nwgrd1 lives in the directory nwgrd1, and has the following component files: -rwxr--r-- 1 warmerda users 32 Jan 22 16:07 nwgrd1/dblbnd.adf -rwxr--r-- 1 warmerda users 308 Jan 22 16:07 nwgrd1/hdr.adf -rwxr--r-- 1 warmerda users 32 Jan 22 16:07 nwgrd1/sta.adf -rwxr--r-- 1 warmerda users 2048 Jan 22 16:07 nwgrd1/vat.adf -rwxr--r-- 1 warmerda users 187228 Jan 22 16:07 nwgrd1/w001001.adf -rwxr--r-- 1 warmerda users 6132 Jan 22 16:07 nwgrd1/w001001x.adf Sometimes datasets will also include a prj.adf files containing the projection definition in the usual ESRI format. Grids also normally have associated tables in the info directory. This is beyond the scope of my discussion for now. The files have the following roles: * dblbnd.adf: Contains the bounds (LLX, LLY, URX, URY) of the portion of utilized portion of the grid. * hdr.adf: This is the header, and contains information on the tile sizes, and number of tiles in the dataset. It also contains assorted other information I have yet to identify. * sta.adf: This contains raster statistics. In particular, the raster min, max, mean and standard deviation. * vat.adf: This relates to the value attribute table. This is the table corresponding integer raster values with a set of attributes. I presume it is really just a pointer into info in a manner similar to the pat.adf file in a vector coverage, but I haven't investigated yet. * w001001.adf: This is the file containing the actual raster data. * w001001x.adf: This is an index file containing pointers to each of the tiles in the w001001.adf raster file." |
| Availability date: | 20040416 |
| Metadata version: | 3 |
| Keydate: | 2004-04-01 15:29:26+00 |
| Editdate: | 2009-12-03 21:40:17+00 |