Since the first recipe of the chapter, we've been working with vector data; of course, GeoServer is also there to serve raster data. Moreover, while you may think that raster data doesn't need a style, this is only true for a small set of them. Most people think of raster data as aerial imagery, where the surface of the Earth is represented with true colors. In fact, this paradigm has been greatly enforced by the huge popularity web mapping applications have gained in the last decade.

However, there is a great variety of different raster data containing data about any parameter a sensor can measure, from elevation to temperature to satellite radar scenes and so on. Visualization of all this data makes more sense when you classify them and choose a set of colors. You will apply this technique to elevation data in this recipe.

For this recipe, we need a Digital Elevation Model (DEM). As usual, we will use freely available open source data. Go to https...