| Authors | Tran et al. |
| Country | Forest Research Institiute, Korea |
| Paper (PDF) | View paper |
| Category | Planning & Inventory › Remote sensing & mapping |
ALS and HMLS provide good point clouds. Both together could be benefitial to cover tree tops as well as DBH
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Diameter at breast height (DBH) and total tree height are the two foundational mensuration variables in forest inventory, underpinning timber volume estimation, biomass calculation, and site productivity assessment. Laser scanning technologies — spanning handheld mobile laser scanning (HMLS), airborne laser scanning (ALS), and integrated approaches that combine both — offer alternatives to traditional manual measurement, with distinct trade-offs in accuracy, coverage, and operational cost. HMLS systems, such as the Zebedee ZEB-REVO or Leica BLK2GO, are carried by a field operator walking through the stand, producing dense, ground-level point clouds that capture stem geometry with high fidelity; DBH estimates from HMLS typically achieve root-mean-square errors of 1–3 cm compared to manual caliper measurements, making them highly competitive for this parameter. ALS systems, mounted on aircraft or helicopters, provide top-down point clouds at landscape scales and excel at capturing canopy height structure, delivering tree height estimates within 0.5–2 m of field-measured values for open-canopy stands, though dense canopy occlusion and lower point density near the ground limit their utility for DBH estimation in many forest types. Integrated ALS and HMLS approaches exploit the complementary strengths of both platforms: ALS data define canopy heights and crown boundaries at stand scale, while co-registered HMLS point clouds provide precise stem-level data including DBH, stem taper, and understorey structure that ALS cannot resolve. Comparative studies consistently show that integrated workflows produce more complete and accurate stem maps than either technology alone, particularly in structurally complex mixed-species forests. In Australia, comparative assessments have been conducted in eucalypt forests of southeastern Australia and in radiata pine plantations, where researchers have validated that HMLS provides superior DBH accuracy while ALS remains essential for wall-to-wall height and volume modelling across large areas. The choice of technology is therefore determined by the inventory objective, stand structure, spatial extent, and available budget.
| Field | Value |
|---|---|
| Company | Tran et al. |
| Country | Forest Research Institiute, Korea |
| Type | Paper |
| Year | 2025 |
| FWPA RD&E | 7.3 |