2004 UC Proceedings Abstract
 Modeling River Water Surfaces Using LiDAR Technology and ArcGIS Spatial Analyst Track: Cartography and Map Production Author(s): Richard Duncan LiDAR (Light Detection and Ranging) is a powerful technology for deriving very accurate DTMs. However, developing an aesthetically pleasing cartographic representation of the topography, particularly where it involves variably inclined water surface features like rivers or canals, is a significant challenge. LiDAR returns from water surfaces are known to be of suspect accuracy, having a large standard deviation about the true (mean) value, and their injudicious use can produce unexpected results-like water flowing uphill. Because water generally flows downhill, and for mapping purposes can be deemed to have a flat surface (at least locally), it is desirable to have contour lines crossing the water surface at the appropriate interval where the water elevation corresponds with terrain elevation on either side of the stream. This paper describes the methodology for extracting LiDAR data to derive accurate elevations for sloping water surfaces and integrating those surfaces seamlessly with the surrounding terrain. Richard Duncan GeoEngineers, Inc. GeoSpatial Services 8410 154th Ave NE Redmond , WA 98052 US Phone: 425-861-6021 Fax: 425-861-6050 E-mail: rduncan@geoengineers.com |
|||||
