The National Science Foundation recently awarded a five-year $4 million renewal grant to researchers at the University of Florida and the University of California at Berkeley for the National Center for Airborne Laser Mapping, known as NCALM.
UF was the first university in the nation to purchase and operate a survey-grade airborne LIDAR system in 1998. Researchers mounted the system in a Cessna 337 at Gainesville’s airport. Pumping out 5,000 laser pulses a second, they mapped beaches, marshes, flood zones, sink holes, highways and forests in Florida and nearby states.
The NCALM authored this good introductory article on laser scanning - http://ptonline.aip.org/journals/doc/PHTOAD-ft/vol_60/iss_12/41_1.shtml (published in Physics Today)