It turns out that the road less traveled…is not a road.
In recent years, improvements in the design and efficiency of unmanned aerial vehicles (UAVs) have made them a powerful tool for 3D geographical mapping. Forests, a critical stabilizing force for climate, are home to 80% of the world’s terrestrial biodiversity, and 1.6 billion people rely directly on forests for their survival. Although aerial mapping of forested terrain has been possible since the invention of the hot air balloon, recent technological developments have enabled a much more detailed understanding of overall forest health and the complex ecosystems within.
Point Clouds Lead to Pointed Resolutions
The term “remote sensing” refers to sensors mounted on aircraft or satellites. These sensors utilize electromagnetic energy as a means of measuring target characteristics.
A collection of data points defined by a given coordinates system, or point cloud, is used to create a 3D model of an object or terrain. Tomography (imaging by sections) scanning enables continuous forest mapping on a global scale, and enhancements in data point mapping have resulted in highly accurate and realistic spatial and temporal resolution.
Various algorithms can be used to filter and cross-check data in order to ensure that variables such as cloud cover or other atmospheric moisture, wind, and solar reflection do not distort the accuracy of spectral imagery.
In addition to commercial applications, remote sensing data is currently being used by the United Nations council in the creation of targeted Sustainable Development Goals. Forest cover monitoring and deforestation detection via remote sensing is integral to creation and enforcement of global policy objectives, including the following:
- Protect, restore, and promote sustainable use of terrestrial ecosystems
- Combat desertification
- Halt and reverse land degradation
- Halt biodiversity loss
Using modeling from radar data collected by satellites positioned to track areas of interest such as the Amazon rainforest, Early Warning Systems (EWS) serve as a fundamental component of public policies focusing on preventing and reducing forest biomass loss.
Way Leads on to Way
Forests are dynamic structures. Below the dense canopies of trees, multilayered ecological processes are continually unfolding: growth, decay, diversification. In order to better understand how forests function, it is necessary to be able to map not just the crowns of the trees, but the biomass beneath them.
Fortunately, the first UAVs capable of navigating within a stand of trees have already been able to collect valuable data. Using laser scanning methods and multi-view sterophotogrammetry, as well as segmentation, scientists have been able to identify the composition and density of different types of trees in a forest stand, as well as the age and characteristics of individual trees, among other things.
We now have the ability to model changes (e.g. logging, drought-induced tree mortality, natural disturbances) happening within forests in an accurate and timely fashion. Moreover, data collected can be used to simulate trends, such as the rate of regrowth of particular species after a forest fire. Data simulations such as these can be employed in practices for effective management of forests; for example, engaging in sustainable logging and conserving biomass and diversity.
Remote sensing via UAV drones gives us the ability to systematically observe and model trends in Earth’s essential forests. And that will – hopefully – make all the difference.