Dual Wavelength Echidna LiDAR (DWEL) was developed by the University of Boston, University of Massachusetts, Boston, University of Massachusetts, Lowell, USA, and CSIRO, Australia (Douglas et al., 2012). Another one is the Salford Advanced Laser Canopy Analyser (SALCA) developed by the University of Salford, UK.
Both of these instruments were purpose-built to measure structural characteristics of forest canopies. Selection of wavelengths (near- and middle-infrared) is based on different reflectivity from foliage and branches. Index is developed based on these two spectral bands. Results of combination of these two wavelength are shown in figure below.
