Benchmarking Trends in Airborne LiDAR Pre-Processing Algorithms for Forestry Research
摘要
We conducted a systematic review of 837 scientific articles published between 2016 and 2023 to examine how ALS pre-processing algorithms have been used in forestry, focusing on data acquired from manned platforms and on three pre-processing steps: ground filtering (GF), digital terrain model (DTM) interpolation, and individual tree crown delineation (ITCD). This review was combined with a benchmark of widely used algorithms, evaluated at three representative point densities (low: 1 pts/m2; medium: 8 pts/m2; and high: ~18.9–23.7 pts/m2) and three study areas spanning contrasting temperate forest environments in the United States. We asked how algorithm choices and study designs have evolved in recent forestry ALS literature, and which methods are more robust across point densities and forest contexts, including whether calibration meaningfully improves key forest parameters retrieval such as tree height and crown diameter.
Recent FindingsThe review showed the dominance of area-based approaches, while revealing an increasing adoption of tree-level studies, higher point densities and repeated ALS acquisitions supporting multi-site and multi-temporal analyses. It also showed an increasing share of studies using publicly available ALS datasets. Informed by literature trends, the benchmark provided complementary evidence on algorithm behavior under operational conditions: Cloth Simulation Filter and Inverse Distance Weighting performed consistently well for GF and DTM interpolation, whereas no single ITCD algorithm clearly outperformed others. Input settings calibration had limited impact on tree height estimation but improved crown diameter retrieval, particularly at low density.
SummaryBased on our findings, no single ALS processing workflow can be recommended universally, as algorithm performance and calibration benefits depend on point density and forest context. Calibration showed limited effects on tree height estimation but improved crown diameter retrieval, particularly at low density. We therefore provide density-aware, context-specific recommendations to support reproducible ALS processing workflows in forestry studies.