Can pseudo waveforms from discrete point clouds represent the vertical structure of divergent canopies?

Forest three-dimensional structure is important information for forest projection, and has shown promising applicability in simulating canopy radiative transfer. Light Detection And Ranging (LiDAR) technology provides a cost-effective way to retrieve forest structure. Compared with other methods, the pseudo-waveform (PWV) is a simpler but more robust way to obtain vertical structure information, but has only been tested in limited regions for two main limitations. First, given the cost of collecting in situ LiDAR observations, considering a comprehensive evaluation of the response of PWVs to canopy architecture remains impossible. Second, while radiative transfer models (RTMs) generate reasonable LiDAR signals, representing tree objects in a cost-effective way is still a bottleneck for large-scale simulation and analysis. As a necessary evaluation for retrieving forest structure from LiDAR, a light RTM was employed to simulate PWVs in this study. Based on the analysis, we aim to answer the following questions: 1) Can the tree objects be represented in a simpler way and with limited metrics, 2) Are the PWV responses reasonably to the variation in canopy architectures under uniform scenes, and 3) What is the PWV response to tree height uncertainties.