Using stereo-pair scanning electron images, a program called MeX can create three-dimensional models of structures. These can be used to determine the structure's width, depth and volume.
This example shows the model and data generated for an impact crater. The crater was made by the impact of a grain of cometary dust on the surface of NASA's Stardust spacecraft.
A stereo anaglyph image of the crater and data generated from its 3D model. The right-hand graph represents the height and depth information obtained from a cross section of the crater.