How many orthoquads would you need to cover completely the town of Northampton? Explain the strategy you followed to come up with that information.

Look at the next image: which feature is the arrow pointing at? (hint: go to your map, zoom into that area in the orthophoto and then, activate the topo layer).

Figure 4: Feature Id?ntification

What is the approximate elevation of that feature? Provide the units too.

Look at the next image. Find that spot in your map, and compare the topo view with the orthophoto view.

Figure 5: Topo/Orthophoto comparison

Do you see any difference? What has happened? Which data is more recent? Justify your response or provide any source that helped you figure this out.

Extra credit: Provide some interesting links to international GIS data that were not already mentioned in http://linuxlab.sbs.umass.edu/fossgis/index.php?title=Web_GIS_data_resources