I have satellite images of night-time lights all over earth. I also have a vector shapefile of country boundaries including the largest cities on earth. I want to use buffers to capture a certain amount of light pollution emanating from cities that is viewable from the raster image.
How do I use buffers to analyze pixels (or some aspect of the raster data) within the buffer area? I assume I will want to assign some value to a certain pixel and then total those values by using the buffer to analyze all data within the buffer.
I have attached a snip of what I am working with. I am very new to GIS still, so bear with me.
I am using QGIS 2.0.