Project Anvil (Applied Analysis Spectral Analytical Program) is a software program that is currently part of the ERDAS imagery processing package. Anvil takes MultiSpectral imagery, using ERDAS, and goes inside of a pixel to determine the content of the pixel, rather then classifying the whole pixel as current techniques do. Current technology can classify down to as little as 20% of a pixel. This means that if the object you are looking for takes up only 20% of the area of the pixel, you should still be able to identify it. A quick example of the process is as follows. You have a SPOT or Landsat Multispectral image of an area and you are looking for something specific, i.e., concrete roads. By going into the image and already knowing spectral properties of many items in the scene, i.e. grass, trees, etc, you can remove all of these and if the remaining spectral properties match that of the type of road you are looking for, that basically means you have road there.
Current projects include: