Datové sady / Barataria Bay, LA (G200) Bathymetric Digital Elevation Model(30 meter resolution) Derived From Source Hydrographic SurveySoundings Collected by NOAA


Barataria Bay, LA (G200) Bathymetric Digital Elevation Model(30 meter resolution) Derived From Source Hydrographic SurveySoundings Collected by NOAA

Vydavatel National Oceanic and Atmospheric Administration, Department of Commerce

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ongoing release of a series of related datasets

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Creative Commons CCZero

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Popis

Bathymetry for Barataria Bay was derived from six surveys containing47,706 soundings. No surveys were omitted. The average separationbetween soundings was 134 meters. The surveys dated from 1933 and 1934.The range of soundings was from 0.2 meters to -39.6 meters at mean lowwater. Mean high water values of 0.2 or 0.3 meters were assigned to theshoreline. Five points were found that were not consistent with the rest of thedata and were removed prior to tinning. DEM grid values outside theshoreline (on land) were assigned null values (-32676).Barataria Bay has thirteen 7.5 minute DEMs and two one degree DEMs.The 1 degree DEMs were generated from the higher resolution 7.5minute DEMs which covered the estuary. A Digital Elevation Model(DEM) contains a series of elevations ordered from south to northwith the order of the columns from west to east. The DEM isformatted as one ASCII header record (A- record), followed by aseries of profile records (B- records) each of which include a shortB-record header followed by a series of ASCII integer elevations(typically in units of 1 centimeter) per each profile. The lastphysical record of the DEM is an accuracy record (C-record).The 7.5-minute DEM (30- by 30-m data spacing) is cast on theUniversal Transverse Mercator (UTM) projection. It provides coveragein 7.5- by 7.5-minute blocks. Each product provides the samecoverage as a standard USGS 7.5-minute quadrangle but the DEMcontains over edge data. Coverage is available for many estuaries ofthe contiguous United States but is not complete.