Module 4 - Remote Sensing - Accuracy Assessment of Land Use and Land Cover Classification

Map of Accuracy Assessment of Land Use and Land Cover,
Pascagoula, Mississippi, based on Google Street View

This week we did a virtual "Ground Truth" accuracy assessment of our Land Use and Land Cover interpretation and classification from last week.

Here is the map from last week, with 30 sample points to be checked against Google Earth Street View.  The points were more-or-less randomly scattered across the area, however, none are located in the southwest quarter of the map, because this area is covered with large areas of water and wetlands that are not visible from Street View.  A few sample points are located along the coast, in areas that could be seen from the shore-side roads.

The procedure was to find the location of each sample point on Google Maps, satellite view, then go into Street View and ascertain what is actually at that spot, and if it follows the classification that was given earlier for that spot.
In my map, 11 of the 30 sample locations returned incorrect classifications, giving an accuracy of 63.3%.  Most of the errors resulted from the misinterpretation of an actual Commercial and Services area (class 12) as a Commercial and Industrial Complex area (class 15).  Also, some areas that I earlier classified as Forested Wetlands (61) are probably Mixed Forest Land (43); in other words, forested areas on dry land.

Residential areas, lakes, rivers and roads are very easy to classify from aerial imagery, because they are very distinctive in geometry, details, and textures.  However, a couple of spots that looked like residential houses turned out to be commercial locations, and vice-versa.