In the heart of Italy, researchers have developed a groundbreaking method to measure olive tree heights using satellite imagery, a discovery that could revolutionize the agricultural and energy sectors. Raffaella Brigante, a researcher from the Department of Engineering at the University of Perugia, has led a study that leverages high-resolution satellite images to estimate tree heights, a critical parameter for assessing biomass, carbon stock, and canopy volume.
The traditional methods of measuring tree heights, such as using drones or ground-based surveys, can be time-consuming and costly, especially over large areas. Brigante’s innovative approach uses very-high-resolution (VHR) satellite imagery and shadow analysis to provide a more efficient and cost-effective solution. “The primary advantage of this method over drone usage lies in its greater efficiency over large areas,” Brigante explains. “Drones are typically limited to a few hectares per flight due to battery constraints. Therefore, for areas larger than a few hectares, the method proposed here is faster and more cost-effective, especially when using archived satellite imagery.”
The method involves a mathematical model that incorporates slope and aspect information derived from a Digital Elevation Model (DEM) in a Geographic Information System (GIS) environment. By leveraging sun position data embedded in satellite image metadata, the model calculates tree heights with remarkable accuracy. The study, published in Applied Sciences (translated from Applied Sciences), validated the methodology by comparing the estimated tree heights with altimetric data obtained through drone surveys.
The implications of this research are vast, particularly for the energy sector. Accurate measurement of tree heights can significantly enhance carbon stock assessments, a crucial factor in carbon trading and renewable energy projects. “This approach enables rapid and cost-effective measurements compared to other techniques, such as UAV surveys,” Brigante notes. “It allows for the analysis of very large areas much more efficiently than ground-based or drone measurements and benefits from the wide availability of archived satellite images, which can be purchased at lower prices compared to new acquisitions.”
The method’s potential extends beyond olive trees. While the study focused on olive trees due to their unique canopy structure, the approach could be applied to other tree species or even to buildings and other vertically developed structures on the ground. This versatility makes it a valuable tool for environmental monitoring, sustainable agricultural management, and broader spatial analysis applications.
Looking ahead, the development of a specialized GIS tool, such as a plugin for an open GIS platform like QGIS, could streamline and expedite operations. This tool would make the methodology more accessible to a wider range of users, from agricultural scientists to energy sector professionals. “To streamline and expedite operations, the development of a specific tool, such as a plugin for an open GIS platform like QGIS, is under consideration,” Brigante states.
As the world continues to grapple with climate change and the need for sustainable practices, innovations like Brigante’s offer a beacon of hope. By providing a more efficient and cost-effective way to measure tree heights, this research could play a pivotal role in shaping the future of the agricultural and energy sectors. The potential for widespread adoption and application of this methodology is immense, paving the way for more accurate and sustainable environmental management practices.