GIS Data Catalog

Cartographic Greyscale Hillshade for Puget Sound lowlands and Cascade Range

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Summary

DEM and greyscale hillshade were created to serve as generalized cartographic backdrop where a regional view of elevation data is needed rather than high elevation accuracy.

Description

A smoothed and generalized version of the 28 meter NED elevation data and associated hillshade NED 28 meter data was resampled and generalized (smoothed) to reduce graphic artifacts.

Layer information

Layer Name	SURFACE_NEDDEMCartographic
Subject Category	Imagery
Title	Cartographic Greyscale Hillshade for Puget Sound lowlands and Cascade Range
Feature Count	1
Feature Type	Raster
Next Update	As needed
Spatial reference	None
Control ID	None
Place Keywords	None
Theme Keywords	Topography, Elevation Model, Digital Elevation Model, Hillshade, Elevation
Supplemental Information	All these datasets exist only at KeyRegion index level.

Attribute information

OBJECTID From ESRI	Description Internal feature number. Domain Sequential unique whole numbers that are automatically generated.
Shape From ESRI	Description Feature geometry. Domain Coordinates defining the features.
Shape_Length From Esri	Description Length of feature in internal units. Domain Positive real numbers that are automatically generated.
Shape_Area From Esri	Description Area of feature in internal units squared. Domain Positive real numbers that are automatically generated.
MosaicID No Source Noted	Description Not Found Domain Not Found

Contact information

Maintained by	KCGIS Center
Primary	KCGIS Center giscenter@kingcounty.gov

Terms of Use

License	Terms of use and copyright

Summary

DEM and greyscale hillshade were created to serve as generalized cartographic backdrop where a regional view of elevation data is needed rather than high elevation accuracy.

Description

A smoothed and generalized version of the 28 meter NED elevation data and associated hillshade NED 28 meter data was resampled and generalized (smoothed) to reduce graphic artifacts.

Contact information

Maintained by	KCGIS Center
Primary	KCGIS Center giscenter@kingcounty.gov

Terms of use and copyright

License	Terms of use and copyright

Change history

6/1/2005	Original NED 10-meter data by county has previously existed. In order to provide as seamless file and SDE image mosaic a smoothed generalized composite was created for the entire Puget Sound area. This type of mosaic already existed from the USGS 30 meter data, but starting with the 10 meter data allowed more artifacts to be removed Each county 10 meter DEM was processed in ArcInfo 9.x Workstation using the following command sequence: ARC - FILTER each DEM with a low pass filter (4x) GRID - RESAMPLE to 70 feet (based on an earlier version done only for King County) GRID - MERGE all grids to a single grid GRID - GRIDCLIP to form a neatline boundary GRID - FOCALMEAN using a RECTANGLE 3x3 matrix to remove scan lines ARC - HILLSHADE using an azimuth of 50 degrees and default bearing (315) with the SHADE argument ARC - GRIDIMAGE hillshade grid to tif image Copy grid reg_ned070 and image reg_nedghs070 to plibrary3/keyregion/elevation/.