Comparison of Discrete Return and Waveform Airborne Lidar Derived Estimates of Fractional Cover in an Australian Savanna

The advance of commercial airborne lidar systems from discrete-return to waveform recording instruments has made repeatable estimates of biophysical variables from these different methods questionable. Using an experimental airborne waveform lidar dataset acquired in an Australian savanna, this study presents a method for the derivation of canopy/ground backscatter coefficients from waveform lidar and a comparison of discrete return and waveform approaches to the estimation of fractional cover. Despite limited validation, the results indicate that waveform estimates of fractional cover can provide consistently higher accuracy than discrete return estimates under varying survey properties. Ongoing work using raw waveform data across larger areas and 3D radiative transfer simulations aims to develop a quantitative understanding of the impact of disparate sensor and survey properties on the detection of change in vegetation structure using commercial lidar instruments.