By Teri Greene
The study, “Using ICESat-2 to Estimate and Map Forest Aboveground Biomass: A First Example” in the journal Remote Sensing, shows how NASA’s Ice, Cloud and land Elevation Satellite-2, or ICESat-2, can be used to estimate aboveground biomass, or AGB, of forests and map its distribution.
Narine said limited information on the three-dimensional structure of forests has contributed to uncertainties in determining carbon budgets. However, ICESat-2 can capture this information using a laser-based lidar (light detection and ranging) instrument.
Lidar facilitates direct three-dimensional structural measurements, and using this technology from a space-based platform translates to exciting possibilities for assessing forest resources up to global scales, Narine said.
Knowing the capabilities of ICESat-2 allows for a better understanding of the satellite’s capabilities and limitations for characterizing vegetation.
“With ICESat-2 providing elevation measurements globally, a plethora of indicators of ecosystem health and function — including a key surrogate measure of forest AGB — can be potentially estimated to support sustainable management of forests,” Narine said.
The ICESat-2 mission was primarily designed to capture ice measurements, but its capture of data over vegetated areas offers investigators broader insights into ecosystem structure and the potential to contribute to the sustainable management of forest ecosystems.
Peter Krzystek, Professor for Photogrammetry and Remote Sensing at Munich University of Applied Sciences tells about new investigations into the 3D mapping of forests.
Modern remote sensing sensors offer completely new possibilities for an extensive and detailed 3D capture of tree populations, making it possible to map at very large-scale. In particular, LiDAR is today an established technique for fast and highly accurate 3D scanning from the aircraft, helicopter or drone where pulses of visible or near-infrared laser light at a particular wavelength are used to create 3D images. These 3D images are typically made up of a high density of data points, known as ‘point clouds’. The new full waveform technology, which reconstructs the complete path of the laser beam through the vegetation, makes it possible to map the forest structures in 3D more precisely. Moreover, digital aerial cameras enable a detailed reconstruction of the forest surface and provide – if fused with LiDAR data – extra spectral information in the infrared range for a characterisation of the tree species. All in all, these new technologies are ideally suited for the automatic and cost-effective collection and characterisation of forest stands.
This article addresses professionals like foresters, ecologists, project developers, certifiers, and environmentalists (in the following called natural resources managers) who are new to the field of remote sensing or who want to update their basic knowledge.
What will you learn? You will learn to
distinguish between various data collection methodologies,
understand the pros and cons of different data sources, and
select the right data set to answer your questions efficiently.