Automated measurements of terrain reflection and height variations using an airborne infrared laser system

Abstract A pulsed near-infrared laser system was converted to determine laser height and reflection values in airborne operations. The laser produces precise traces of the terrain and vegetation canopy and tree measurements can readily be made in open forests since the laser beam frequently penetrates openings in the canopy cover. The reflection measurements were useful in discriminating between vegetation type and density. Using the combined laser height, laser reflection and reflection variability parameters, it was possible to arrive at a simple semiautomated terrain classification which allowed a distinction between conifer and broadleaf forests and terrain with low-growing vegetation cover. The classification of individual trees into coniferous and broadleaf of different height classes is demonstrated. The data is in digital form and can be incorporated into geographic information systems. Considering that these measurements were made at a single wavelength (904 nm), it is clearly evident that high-r...