This week the focus was on using and understanding DEMs and TINs. DEMs are digital elevation models, and TINs are triangular irregular networks. Both are remotely sensed imagery that are used to convey the three-dimensional surface of the Earth. This can be used for a wide variety of applications that require knowledge of what the terrain looks like.
DEMs and TINs are similar in many ways but there are differences between the two (Bolstad 2016, 68). The most obvious difference is that is a DEM is a raster and a TIN is a vector. The other major difference is that a TIN is able to convey elevation, slope, and aspect simultaneously while a DEM must be geoprocessed into three different layers to show each one of those elements.
TINs can be symbolized to emphasized different characteristics such as slope. It is also possible to apply an outline to the edge of each triangle, so that when you are looking to click on a particular triangle to find its information it is easier to identify a single one. Contour lines may also be applied so that differences in elevation are easier to discern.
Bolstad, P. (2016). GIS Fundamentals: A First Text on Geographic Information Systems (5th ed). Eider Press.
No comments:
Post a Comment