LIDAR

http://www.kval.com/news/local/102918079.html

LIDAR uses light to remotely sense and determine distance of an object, this is often done using laser.  It is useful in contour mapping to a great deal of precision.  Some satellites integrate this technology into their systems.  LIDAR has many uses, one great example is the ability to determine the biomass of a given area for environmental purposes.  The image above is showing how LIDAR is used to boost the ecosystem of this area by determining its vegetation density.