Muscongus Bay, ME (N060) Bathymetric Digital Elevation Model (30 meter resolution)
Derived From Source Hydrographic Survey Soundings Collected by NOAA |
Bathymetry for Muscongus Bay was derived from nine surveys containing 109,649 soundings.
No surveys were omitted. The average separation between soundings was 43 meters. Of
the nine surveys used, one dated from 1943 and the rest dated from 1944. The total
range of soundings was 2.1 meters to -70.4 meters at mean low water. Mean high water
values between 2.7 and 2.9 meters were assigned to the shoreline. Eighteen points
were found that were not consistent with the surrounding data. These were removed
prior to tinning. DEM grid values outside the shoreline (on land) were assigned null
values (-32676). Muscongus Bay has seven 7.5 minute DEMs and two one degree DEMs.
The 1 degree DEMs were generated from the higher resolution 7.5 minute DEMs which
covered the estuary. A Digital Elevation Model (DEM) contains a series of elevations
ordered from south to north with the order of the columns from west to east. The DEM
is formatted as one ASCII header record (A- record), followed by a series of profile
records (B- records) each of which include a short B-record header followed by a series
of ASCII integer elevations (typically in units of 1 centimeter) per each profile.
The last physical record of the DEM is an accuracy record (C-record). The 7.5-minute
DEM (30- by 30-m data spacing) is cast on the Universal Transverse Mercator (UTM)
projection. It provides coverage in 7.5- by 7.5-minute blocks. Each product provides
the same coverage as a standard USGS 7.5-minute quadrangle but the DEM contains over
edge data. Coverage is available for many estuaries of the contiguous United States
but is not complete. |
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