Changing the spatial extent or resolution of rasters

With reference to raster geometry, so far we have only dealt with operations where the raster extent is manually reduced by selecting a certain combination of rows and columns to retain (refer to Chapter 4, Working with Rasters). In this chapter, we will review more operations that provide us with the freedom to modify the raster geometry of datasets according to our specific requirements.

In this section, we will see how we can change the extent or resolution of rasters without modifying the underlying grid arrangement. This category includes operations such as merging rasters, cropping, or aggregating/disaggregating raster cells. In the next section, we will see how the underlying grid (and possibly the CRS) can be modified through resampling and reprojection.

In the first few examples of this chapter, we will work with a DEM of the area surrounding Haifa, and experiment with the modification of raster extent and resolution. A DEM is...