For our first Remote Sensing lab assignment, we began with the basics of the visual interpretation of aerial photographs. In our first exercise, we simply identified regions in the image (above) that fall along a five-step scale in tone (light to dark colors) and texture (smooth to rough). These two features (tone and texture) can help us understand what we are looking down on in aerial images. In the image above, for example, the very smooth area (lower left, in blue) is water while a very "rough" area is the section of residential housing left of center.
The second part of the exercise had us identifying objects using one of several strategies: Shape & Size, Shadows, Patterns, or Association. Some objects are quite obvious just by their shape and size. I happen to be quite familiar with docks and piers, for example, and the pier in the image above was easy for me to identify by shape. Similarly, the water tower may not be easily identifiable with only a top-down view, but the shadow is quite distinct to anyone who has ever lived in the mid-west. The parking lot appears to have a distinctive herringbone pattern to it. Finally, we can use association to identify features. The beach is not particularly distinctive in this view. However, we know we have water in the image (from the wave pattern) so the association of this feature adjacent to the water is easy to make.
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