Summary

Description

Bathymetry for the Indian River was derived from eleven surveyscontaining 150,082 soundings. Five older, less accurate,overlapping surveys were omitted, and the overlap from one older,less accurate survey was omitted prior to tinning. The averageseparation between soundings was 76 meters. One survey in thenorth dated from 1941. The ten remaining surveys dated from1976 to 1983. The total range of sounding data was 0.3to -13.2 meters at mean low water. A mean high water valueof 1.0 meters was assigned to the shoreline. Eight points werefound that were not consistent with the surroundingdata. These were removed prior to tinning. DEM grid valuesoutside the shoreline (on land) were assigned null values (-32676).The Indian River has thirteen 7.5 minute DEMs and a single one degreeDEM. 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.