Geographic Resources Center
Metadata for cnnndem
Table of Contents
Originator: Geographic Resources Center
Title: County-Level DEM
50 meter resolution Digital Elevation Model of Missouri counties.
Generally used in surface modeling, surface viewing, and surface analysis.
These datasets were created by joining the thirty separate USGS
3 arc-second dem datasets that encompass the area of Missouri. The
original datasets had various levels of resolution according to their
latitudinal positioning. All were resampled to the 50 meter resolution
now present and then merged. Most anomalous data points were eliminated
by using a low-pass filter in ARC. The merged set was then clipped by
a 6 kilometer buffered state polygon. All counties were buffered by
1 kilometer and then used to clip out the county-level sets now available.
Some anomalous points may still be present along join-lines of the
separate dems. These should be easily detected and eliminated by the
use of a variety of GIS applications available.
The join-lines can be considered the same as those of the 1:100,000
quadrangles of Missouri. Thus, the user can be advised to inspect their
county-level dem along these lines (if applicable).
Although this dataset may be used for some hydrological analysis, the user
should be aware that these data may not be applicable for smaller-streams.
James D. Harlan
Aug 6, 1997i
Reviewed by James D. Harlan, 7 August 1997.
A state-level DEM is available at MSDIS and could possibly be provided
upon special request. However, the size of the dataset approaches 1gig
and is not appropriate for dissemination on a wide basis through the
The USGS has a variety of DEMs available on various web sites.
United States Geological Survey.
Defense Mapping Agency
This DEM could be referred to as 3 arc-second, 1:250,000, or
1degree x 1degree. It was originally created by the Defense Mapping Agency
(DMA) and adapted by the USGS to fit as a DEM for their 250,000 (1deg x 1deg)
Many sources were implemented in determining the elevation values for the
dem mesh points with USGS and DMA 24,000 and 25,000 quadrangles being the
most often cited. So, the scale of 250,000 is deceiving. The dem is only
fitted to the 250,000 quad size or area.
Progress: Data complete
Still under analysis and will be modified or updated accordingly.
Theme_Keyword: County-Level DEM
Place_Keyword: Counties of the State of Missouri
Limitations are generally user-defined and will vary according
to project needs or standards..
Point_of_Contact: See Data_Set_Credit
Missouri Spatial Data Information Service, Department of Geography,
University of Missouri - Columbia.
Native_Data_Set_Environment: AIX UNIX, ARC/INFO version 7.0.4
Originator: United States Geological Survey and Defense Mapping Agency
Title: 3-Arc Second Digital Elevation Models
Attribute_Accuracy_Report: See Logical_Consistency_Report: Not applicable for raster data.
Horizontal_Positional_Accuracy_Value: 50 meters
Horizontal_Positional_Accuracy_Explanation: Resolution as reported
Lineage: See Cloud_Cover
Raster_Object_Type: Grid Cell
Grid_Coordinate_System_Name: Universal_Transverse_Mercator (UTM)
No outstanding attributes other than elevation values.
Entity_and_Attribute_Detail_Citation: Not Available
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Time_Convention: Local Time
Last modified: 97-08-08.07:51:12.Fri