To fix misaligned and improperly referenced spatial data, the first important step is to look at the properties of your layers and figure out the coordinate system information: what is there, and what is missing. If the coordinate system for a layer is unknown, then the data is improperly referenced and will be misaligned when placed on the map. To fix this problem, all you need to do is go into the properties of the improperly referenced layer, find the coordinate system tab, go into geographic coordinate systems, and select a coordinate system. The coordinate system you select should be the one that was originally assigned to the data before it was lost. The project-on-the-fly feature of arcmap will make the layers line up nicely even if they have different coordinate systems. If you want to match up the coordinate systems of the layers so that they are all the same, you can use the project tool to permanently alter a layer’s coordinate system.
An advantage to using remotely sensed Landsat data for geographic analysis is that new information is released every 16 days, so it is always possible to have up to date data. Another advantage is being able to compare images all the way back to 1972. The best part? All the data is free to access and use.