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Small-Scale Home > Data Download >> Color United States Shaded Relief – 200 Meter Resolution


 

Map Layer Info

     
 
Color United States Shaded Relief – 200 Meter Resolution

What this map layer shows:

The shape of the land surface of the United States, in color and at a resolution of 200 meters.

Also available is Color North America Shaded Relief – 1 Kilometer Resolution.

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Background Information
Sample map Sample Map
The National Elevation Dataset (NED) is a raster product assembled by the U.S. Geological Survey (USGS), designed to provide national elevation data in a seamless form with a consistent datum, elevation unit, and projection. Each grid cell in the national elevation model has a value that represents the average height above sea level within that cell. Data corrections made in the NED assembly process minimize artifacts, permit edge matching, and fill sliver areas of missing data. Elevation data are an essential part of many earth science applications. They are used for such diverse purposes as providing shaded-relief backgrounds, establishing stratification in land cover classification, doing geometric and radiometric correction of remotely sensed data, and determining landform characteristics such as slope and aspect. The Color United States Shaded Relief – 200 Meter Resolution map layer was derived from NED data and was produced by the National Atlas of the United States® with data provided by the USGS Center for Earth Resources Observation and Science (EROS).

The map layer was produced by combining two images. The first was a color elevation image, created by grouping the elevation values into ranges and then assigning colors to the different elevation ranges. The second was a grayscale shaded relief image, in which a three-dimensional appearance was achieved by determining a gray tone at each point, calculated from the steepness of the slope combined with illumination as if there were a light source in the northwest.

The Color United States Shaded Relief – 200 Meter Resolution map layer is four shaded-relief images showing the terrain of the conterminous United States, Alaska, Hawaii, and Puerto Rico and the U.S. Virgin Islands. A separate image was created for each of the four areas of the United States because, at 200 meter resolution, file size for an elevation mosaic of all of the United States would exceed the processing capacity of some commonly-used GIS and image processing software packages. The image is intended for visual purposes only; the original NED data must be used for conducting analysis and determining elevation values.

The Color United States Shaded Relief – 200 Meter Resolution map layer is available in both a Lambert Azimuthal Equal-Area projection and an Albers Conical Equal-Area projection. Only the Lambert files can be viewed with the National Atlas Map Maker.

 


 

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