New multi-wavelength laser scanners are being used to map forests in more detail than ever before, say researchers at the University of Salford in the UK and elsewhere. They believe that their state-of-the-art systems, which are now able to distinguish between woody and leafy parts of trees, will help give earlier and better data on the impacts of climate change on nature.
The team at Salford has developed a pulsed, dual-wavelength scanner, utilizing 1063 nm and 1545 nm wavelengths to measure the three-dimensional structure of forests and individual trees. The Salford Advanced Laser Canopy Analyser (SALCA) is believed to hold huge promise for ecological studies, adding to the purely spatial information that can be gleaned from conventional lidar scanners.
In their paper, 3D models of the same three trees were derived from scans acquired in ‘leaf-off’ condition, with ‘virtual’ leaves added in the same proportions as the measured leaves. The virtual ‘leaf-on’ tree was then compared with the distribution of leaves derived from manual sampling and found to correspond very well.