How Spaceborne Satellites Enhance Forest Monitoring

How Spaceborne Satellites Enhance Forest Monitoring
by Simon Mansfield
Sydney, Australia (SPX) Jul 25, 2024

Monitoring forest canopy height is essential for assessing forest health, yet traditional methods can be impractical for large regions or varied forest types. Space-based monitoring offers a promising alternative.

Forests play a crucial role in carbon sequestration, water regulation, habitat provision, and biodiversity support. Understanding forest ecosystem functions relies on quantifying parameters such as canopy height, canopy cover, and tree density. Traditional methods like airborne laser scanning (ALS) are accurate but can be limited and costly. Researchers are now turning to spaceborne lidar technology as a more accessible and equally precise alternative.

Lidar, which stands for light detection and ranging, is a remote sensing technology that captures three-dimensional information about the earth's surface. While airborne lidar is highly accurate for measuring canopy height, it lacks spatial coverage and affordability. Spaceborne lidar, particularly using the ICESat-2 satellite, shows great potential for large-scale canopy height estimation, offering broader access to crucial forest structure data.

The study, published in the Journal of Remote Sensing on July 5th, highlights the advantages of ICESat-2. This satellite uses advanced laser technology to measure elevation and vegetation height. Its canopy height measurements, especially when using strong beams at night, are highly consistent with airborne lidar data. ICESat-2 demonstrates a high degree of accuracy in analyzing dense evergreen forests.

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

Researchers aim to integrate ICESat-2 with other high-resolution remote sensing methods to achieve comprehensive canopy coverage details and monitor changes over time. ICESat-2 shows promise for tracking forest recovery and detecting 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 from Nanjing Normal University and corresponding author of the study.

Enhanced forest monitoring can detect changes in carbon storage and address deforestation threats promptly. Ultimately, improved surveillance helps preserve ecosystems vital to the safety and longevity of both inhabitants and surrounding areas.

Research Report:Evaluating the Uncertainties in Forest Canopy Height Measurements Using ICESat-2 Data