Assessing forest health accurately is essential but challenging, especially over large areas and diverse forest types. Traditional methods like airborne laser scanning (ALS) are effective but limited in scope and cost. Space-based monitoring, particularly through lidar technology, offers a promising solution.

Forests are crucial for carbon sequestration, water regulation, habitat provision, and biodiversity support. Understanding forest ecosystem functions requires accurate measurements of parameters such as canopy height, canopy cover, and tree density. However, obtaining these measurements on a large scale has been difficult.

Lidar, or LiDAR, is an advanced remote sensing method that captures detailed 3D information about the Earth’s surface. While airborne lidar effectively measures canopy height, its high cost and limited spatial coverage pose significant challenges. To overcome these limitations, researchers are turning to spaceborne lidar.

The ICESat-2 satellite, equipped with state-of-the-art laser technology, offers a compelling alternative. It provides accurate global measurements of elevation and vegetation height, demonstrating exceptional accuracy in dense evergreen forests and strong nighttime performance comparable to airborne lidar data.

“The ICESat-2 satellite has proven to be a reliable and effective tool for measuring canopy height on a global scale,” said Nitant Rai, a former graduate student at Mississippi State University and lead author of a related study. However, careful selection and calibration over the ICESat-2 dataset are necessary for large-scale canopy height estimation.

By advancing ICESat-2 technology and integrating it with other high-resolution remote sensing methods, researchers aim to achieve comprehensive and detailed estimations of canopy coverage and forest structure. This integration will enable continuous monitoring of structural changes over time, helping track forest recovery and detect potential health issues.

“This study also demonstrates the importance of integrating diverse data sources for forest structure monitoring and highlights the applicability of ICESat-2 in understanding forest structure on a global scale,” said Qin Ma, a professor at Nanjing Normal University and the study’s corresponding author.

Monitoring forest structure data is vital for overseeing forested areas, tracking carbon storage changes, and addressing threats like deforestation. Expanding surveillance efforts worldwide will contribute to preserving essential ecosystems, ensuring the safety and longevity of both their inhabitants and the surrounding areas.

By Impact Lab