SUPERVISOR: Arne NOTHDURFT

PROJECT ASSIGNED TO: Lukas MOIK

Accurate timber measurement is essential in forestry and the wood industry, serving as the foundation for invoicing and holding significant economic importance. However, obtaining precise measurements before transporting timber to sawmills or paper mills is challenging due to the time-consuming and error-prone nature of manual measurement methods. Consequently, most forest owners are unaware of the exact quantity of harvested timber until it is processed at a mill. This underscores the need for efficient and precise measurement techniques.

Recent advancements in ground-based LiDAR technology have facilitated research on digital twins of forest stands, making its application for timber measurement a logical next step. Given the varying requirements for different types of timber, this project is divided into three parts. The first part focuses on measuring stacks of sawlogs on an individual log basis, providing accurate estimates of both the dimensions of the sawlogs and the volume of the entire stack. For lower‑quality assortments, individual log characteristics are less important. Therefore, the second part of the project aims to develop routines for measuring stacks of pulp and energy wood as a whole. The third part addresses the recognition of wood species and the quality of logs within wood stacks.

The modern, LiDAR-based measurement approaches developed in this project have several potential applications. They enable forest owners to obtain accurate estimates of timber quantities and qualities before the timber gets transported to sawmills or paper mills. This could facilitate more sustainable forest management practices by providing near real-time knowledge of harvested timber quantities and qualities. Additionally, these methods can enhance the efficiency of tasks such as stock-taking, thereby reducing labour costs. Furthermore, the digitization of the forest-wood supply chain would be advanced, allowing for improved traceability of timber flows along the supply chain. 

 

Figure 1: Types of laser scanners that can be used to do LiDAR measurements: Appel iPad Pro 10 with built-in LiDAR sensor – a low cost alternative to more expensive scanners (top), RIEGL VZ‑600i – a stationary, terrestrial laser scanner capable of highly accurate measurements (middle) and GeoSLAM ZEB Horizon - a mobile laser scanner allowing for quick measurements (bottom).

Figure 2: Figure illustrating the steps of the timber stack measurement on individual log basis (first part of the project). The process starts with the point clouds of the timber stacks (a). Then the log ends are extracted (b) and subsequently detected (c). In the last step logs can be virtually reconstructed (d) and log parameters are calculated.