Calcasieu Lake, LA (G240) Bathymetric Digital Elevation Model(30 meter resolution) Derived From Source Hydrographic SurveySoundings Collected by NOAA

Bathymetry for Calcasieu Lake was derived from five surveys containing27,199 soundings. No surveys were omitted. The average separationbetween soundings was 98 meters. The surveys dated from 1933 and 1934.The range of soundings for the surveys was 0.2 meters to -19.8 metersat mean low water. Mean high water values between 0.4 and 0.6 meterswere assigned to the shoreline. Five points were found that were notconsistent with the surrounding data. These were removed prior totinning. DEM grid values outside the shoreline (on land) wereassigned null values (-32676).Calcasieu Lake has eleven 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.