Abstract: Synthetic Aperture Radar (SAR) is used from airplanes and from space to image the surface of the earth. This ends up producing an image of reflected amplitude and phase. If we image from 2 different locations we can get 2 images from which we can compute the heights of surface features, similar to the stereo vision provided by our two eyes. I will introduce this sensing methodology, and then give some examples of how we are using it to estimate forest parameters.