A Portable Airborne Laser System for Forest Inventory

were first applied to terrestrial concerns throughout the 1970s Abstract (Link and Collins, 1981; Hoge et al., 1983; Krabill et al., 1984). A simple, lightweight, inexpensive, portable airborne laser Over the past 30 years, the technology has moved from research profiling system has been assembled from off-the-shelf, com- to commercial applications (Baltsavias, 1999). Applications mercially available components. The system, which costs include the use of airborne laser data for creation of digital ter- approximately $30,000, is designed to fly aboard small rain models, monitoring power lines, urban area mapping, and helicopters and single- or twin-engine high-wing aircraft land-cover surveys (e.g., http://www.airbornelasermapping. without airframe modification. The system acquires first- com, last accessed 26 August 2002). Numerous commercial return range and amplitude measurements at data rates up companies now offer turnkey airborne laser scanning systems or to 2000 hz (operator-controlled) and has an operational en- for-hire airborne laser data collection. velope up to 300 m above terrain. The airborne laser profiling Applications of laser technology to forest inventory prob- system includes the laser transmitter/receiver, differential GPS lems, however, remain largely in the research arena, for the fol- receiver, a CCD video camera and recorder, and a laptop com- lowing reasons: puter which interleaves and records the GPS and laser range/ amplitude data. The portable airborne laser system (PALS) was ● Laser data post-processing to derive inventory estimates requires the attention of specialists and, frequently, the applica-