A portable airborne laser system for forest inventory

A simple, lightweight, inexpensive, portable airborne laser profiling system has been assembled from off-the-shelf, commercially available components. The system, which costs approximately $30,000, is designed to fly aboard small helicopters and single- or twin-engine high-wing aircraft without airframe modification, The system acquires first-return range and amplitude measurements at data rates up to 2000 hz (operator-con trolled) and has an operational envelope up to 300 m above terrain. The airborne laser profiling system includes the laser transmitter/receiver, differential GPS receiver, a CCD video camera and recorder, and a laptop computer which interleaves and records the GPS and laser range/amplitude data. The portable airborne laser system (PALS) was designed to acquire forest height measurements along linear flight transects in order to conduct regional or subcontinental forest inventories worldwide. This economical laser system now puts airborne laser mensuration within reach of operational foresters and researchers interested in making rapid forest structure and/or timber surveys in remote areas. PALS has been used to acquire over 5000 km of flight transect data over the state of Delaware.