Digitising Woodland Management | Article 3
In the third and last of our 'Digitising Woodland Management' trilogy exploring digital innovations in woodland management, we focus on mobile technologies which present a new, more accessible avenue of digital innovation in woodland management. This follows the first two articles in the series:
- Digitising Woodland Management: Remote Sensing and Digital Data Processing
- Digitising Woodland Management: Drones
Mobile Technologies
Applications on mobile phones present a new,more accessible avenue of digital innovation in woodland management. The technology is literally at our fingertips and includes measurement tools which employ augmented reality (AR) to measure tree diameters and heights, applications which quantify roadside timber stacks and handheld LiDAR tools. These innovations will be explored in turn and the opportunities they present as well as their applicability discussed.
Augmented reality (AR) is when the real world/physical environment has virtual information imposed on top of it in order to creating a mixed reality (see Figure 1). This is exploited by Swedish mobile measurement apps, KATAM and Arboreal. Arboreal is digital measurement tool facilitating the measurement of trunk diameter at chest height and tree height using the phone camera. The latest iPhones and iPads incorporate LiDAR scanners/sensors in their cameras which the app uses to gather the tree measurements. One of barriers specific, but not unique, to the Northeast and Yorkshire identified by the Forestry Commission is an absence of site-specific information on woodland condition and woodland inventory. Detailed data can be captured, stored and presented using mobile technologies has the potential to revolutionise the quality and quantity information available towoodland owners and managers.
Arboreal is designed to replace manual measurement tools (callipers, tape measures and paper etc.) and a conventional sample area is surveyed. The application is intended to be quicker and more accurate than if traditional measurement methods were used, although in the same way as if you used a tape measure app on a phone or if there are twigs o rbad weather obstructing the view of the map, an over confidence in the app to measure correctly can cause errors. The application doesn’t try to remove the need for an individual to go into the woods but instead streamline the data collection process and store measurements digitally. Furthermore, contextual knowledge for the operator is required to understand the accuracy ofthe measurements is required.
Swedish smartphone app, KATAM, intends to replace traditional analogue measuring tools (KATAM is also discussed in our Drones article). The user directs their camera at the desired area of woodland and based on the recording, is presented with extensive measurement data for the sample plot. In this way the application is user friendly and means that inventory samples canbe collected, processed and stored digitally as the user walk through their woodland. However, despite the technology continuing to advance, the capabilities and accuracy of the app are dependent on the lower parts of trees being unobstructed by vegetation or dense branches to facilitate correct identification of each tree. In addition, the ground level needs to be visible and well defined to allow measurements to be calculated accurately. This means the applicability of the app is restricted to suitable environments.
A number of applications have been developed to measure the volume of roundwood in timber stacks and store and manage the resulting data. The applications can quantify the number of logs as well as extract information about volume and diameter. Applications include Finnish app Trestima; Estonian app Timbeter; Brazilian app Pixlog and American app TimberEye. Timbeter determines the number of logs, volume and diameter of each log, whether in a pile, on a truck or in a container. Apps such as Timbeter are low cost or free and suitable for forest-owners without previous experience or specific knowledge on measuring timber. The user is only required to take a picture of their stacked timber and if the annotated picture is shared, potential buyers are provided the information they require to make a proposal without the need to physically go to the site. If needed measurements can easily and quickly re-measured. The ease of this means that prices can be requested from different companies and the woodland owner can ensure they are getting a good and accurate price for their timber using precise data and with digital evidence.
Mobile Mapping LiDAR scanners
Spaceborne and airborne LiDAR data collection are discussed in separate articles. These are both powerful tools, but their data can be combined with more localised data from terrestrial LiDAR scanners stationed on the ground and handheld LiDAR scanning devices which a user can walk around carrying. Figure 2 shows imagery that can be created using handheld lidar equipment. As part of the SmartForest project in Norway, handheld LiDAR scanning has been identified as an efficient way to map the forest from the ground, producing accurate point clouds which include theforest floor, debris, tree trunks and thick vegetation.
The data also includes a geospatial/locational element. Point clouds are rendered into 3D models using a processing software. A point cloud is a fully 3D format, and this means that it can be viewed from any perspective, no matter what device was used to capture it. It can be viewed from the top-down as if you were seeing the scanned environment from a drone or from any other angle required, but the quality of the different areas of the model may differ depending on the device itself and the location of the device used to collect the data. This is clearly shown in Figure 3 where the limits of point cloud data produced from two different LiDAR scanning technologies – drone (first image) and terrestrial (second image) are illustrated and how the two can be fused to create a more comprehensive picture. In this way advanced and multi-faceted data processing is facilitating the exploitation of digital technologies for the collection of woodland inventory information.