When dealing with misaligned and improperly referenced spatial data, fixing this problem takes a few steps. First, you need to determine the projected coordinate system of the data frame, by looking at the properties of the data frame. Once this information is known, we then have to look through the properties of each individual layer that we are adding to our map, to ensure that the projected coordinate system is the same amongst all of the layers. If a layer does not have properly referenced spatial data, the projected coordinate system will appear as ‘unknown’. We then know that we must choose the projected coordinate system for this layer that matches that of the others.  Projecting-on-the-fly is something ArcMap can do for us that is mostly useful for displaying our maps. It does not alter the data itself, but tries to line up the layers as well as possible so the map looks decent. This is helpful when we don’t know the proper projected coordinate system to use. Manually changing the projection of a layer using the ArcToolbox is a lot better for manipulating data in GIS because the data will actually be changed so that it all aligns and is able to transform the way in which you need it to.

There are many advantages to using remotely sensed Landsat data for geographic analysis. These are images taken from above the Earth’s surface, and every area on earth’s surface gets a new photo every 16 days. This is a pretty well-updated data source in which we can look at the change in land cover between two time periods, and use historical context to explain the difference in appearance between the two images. This is useful for looking at land use change due to natural and anthropocentric disturbances. We can use this analysis to determine large-scale patterns in land use change.