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Creation of digital contours that approach the characteristics of cartographic contours

August 21, 2012

The capability to easily create digital contours using commercial off-the-shelf (COTS) software has existed for decades. Out-of-the-box raw contours are suitable for many scientific applications without pre- or post-processing; however, cartographic applications typically require additional improvements. For example, raw contours generally require smoothing before placement on a map. Cartographic contours must also conform to certain spatial/logical rules; for example, contours may not cross waterbodies. The objective was to create contours that match as closely as possible the cartographic contours produced by manual methods on the 1:24,000-scale, 7.5-minute Topographic Map series. This report outlines the basic approach, describes a variety of problems that were encountered, and discusses solutions. Many of the challenges described herein were the result of imperfect input raster elevation data and the requirement to have the contours integrated with hydrographic features from the National Hydrography Dataset (NHD).

Citation Information

Publication Year 2012
Title Creation of digital contours that approach the characteristics of cartographic contours
DOI 10.3133/sir20125167
Authors Dean J. Tyler, Susan K. Greenlee
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Scientific Investigations Report
Series Number 2012-5167
Index ID sir20125167
Record Source USGS Publications Warehouse
USGS Organization Earth Resources Observation and Science (EROS) Center