Analysis of Side-Lap Effect and Characterization of Understory Vegetation Using Full-Waveform ALS ^†

Airborne full-waveform LiDAR (ALS_FW) is able to register forest structure properties, essential for fire prevention, in more detail than airborne discrete LiDAR (ALS_D). However, few studies have analyzed ALS_FW methodological parameters (i.e., voxel size and assignation value) due to the complexity and lack of processing tools. In this paper we analyze the influence of the pulse density and ALS_FW methodological parameters on the ALS_FW metrics, as well as the characterization of understory vegetation through ALS_FW. Results show that the influence of pulse density on ALS_FW metrics may be modelled and the differences reduced by modifying ALS_FW methodological parameters. Additionally, the potential of ALS_FW for characterizing the mean height (R² = 0.949) and volume (R² = 0.951) of the understory vegetation was also proved.