Exercise 5: Download, view and query raster data
For this exercise, we will download and display a digital elevation model (DEM) stored as raster data. We will perform a simple operation on the raster to create a shaded relief layer in order to better visualize the terrain. And, similar to our data query using the vector model, we will extract a subset of data from our raster using the “raster calculator” tool.
For this example, we will download a DEM for an individual county in North Carolina with a cell size of 20 feet by 20 feet. This is a high-resolution DEM created as part of a statewide flood mapping program using a technology called “light detection and ranging” (LIDAR).