Shading curvature with consideration given to illumination models can add detail to hill-shaded terrain maps in a manner similar to cognitive models employed by map viewers.Ībstract = "Many types of maps can be created by neighborhood operations on a continuous surface such as provided by a digital elevation model. Variations in planimetric and profile curvature seem to be especially effective at highlighting convergent and divergent drainages and variations in erosion rate between or within sedimentary units, respectively. Hill-shaded images combined with curvature enhance the continuity of naturally occurring tonal edges, especially in strongly illuminated areas. A simple conic model indicates that image-tone edges where slope or aspect varies by less than 0.5° are visible on curvature maps. This study illustrates how second derivative maps, in conjunction with hill-shading, can cartographically enhance topographic detail. For example, some maps combine oblique and vertical illumination, with the latter reflecting variations in slope. First derivatives also provide subtle enhancements to hill-shaded maps. Such variables are often used in geomorphic analyses of terrain. These most commonly include first derivatives slope or aspect, and second derivatives planimetric or profile curvature. Many types of maps can be created by neighborhood operations on a continuous surface such as provided by a digital elevation model.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |