Development and performance characteristics of laser-induced fluorescence imaging lidar for forestry applications

Abstract

A laser-induced fluorescence (LIF) imaging lidar was developed to monitor and measure the chemical activities and status of trees and forests. A unique feature of the lidar system was the usage and combination of a nano-second pulse laser and a gated image intensified CCD camera as an imaging detector. The system performance was checked using a ginkgo tree located at a distance of 60 m from the system. By operating the high sensitivity image intensifier with a short time duration of 100 ns, the LIF images of the tree were successfully obtained not only at night but also during the day. The ratio of the LIF image at 740 nm to that at 685 nm could be effective to estimate the chlorophyll concentration inside the leaves. It was shown that the system has the potential for macroscale monitoring of trees remotely and nondestructively.