Canopy Height Layering Biomass Estimation Model (CHL-BEM) with Full-Waveform LiDAR

Abstract

Forest biomass is an important descriptor for studying carbon storage, carbon cycles, and global change science. The full-waveform spaceborne Light Detection And Ranging (LiDAR) Geoscience Laser Altimeter System (GLAS) provides great possibilities for large-scale and long-term biomass estimation. To the best of our knowledge, most of the existing research has utilized average tree height (or height metrics) within a GLAS footprint as the key parameter for biomass estimation. However, the vertical distribution of tree height is usually not as homogeneous as we would expect within such a large footprint of more than 2000 m 2 , which would limit the biomass estimation accuracy vastly. Therefore, we aim to develop a novel canopy height layering biomass estimation model (CHL-BEM) with GLAS data in this study. First, all the trees with similar height were regarded as one canopy layer within each GLAS footprint. Second, the canopy height and canopy cover of each layer were derived from GLAS waveform parameters. These parameters were extracted using a waveform decomposition algorithm (refined Levenberg-Marquardt-RLM), which assumed that each decomposed vegetation signal corresponded to a particular canopy height layer. Third, the biomass estimation model (CHL-BEM) was established by using the canopy height and canopy cover of each height layer. Finally, the CHL-BEM was compared with two typical biomass estimation models of GLAS in the study site located in Ejina, China, where the dominant species was Populus euphratica. The results showed that the CHL-BEM presented good agreement with the field measurement biomass (R 2 = 0.741, RMSE = 0.487, %RMSE = 24.192) and achieved a significantly higher accuracy than the other two models. As a whole, we expect our method to advance all the full-waveform LiDAR development and applications, e.g., the newly launched Global Ecosystem Dynamics Investigation (GEDI).

Joint Study of Above Ground Biomass and Soil Organic Carbon for Total Carbon Estimation using Satellite Imagery in Scotland

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Applications of UAS in Crop Biomass Monitoring: A Review

“…Depth data that do not change with brightness and color can provide additional useful information for complex scenes (Shuqin et al, 2016). At present, the depth sensors on UAV platforms are mainly LiDAR (Wallace et al, 2012;Qiu et al, 2019;Tian et al, 2019;Wang D.Z. et al, 2019;Yan et al, 2020).…”

A Compensation Method of Saturated Waveform for Space-Borne Laser Altimeter

“…In 2003, the ICESat satellite launched by the National Aeronautics and Space Administration (NASA) carried the first Earth observation laser altimeter system, the Geoscience Laser Altimeter System (GLAS) [1], and related research has played an important role in polar ice elevation measurement, monitoring changes in sea ice thickness, forest biomass estimation, global elevation control point acquisition, etc. [2][3][4][5][6]. As laser altimetry has shown better development potential and application prospects in three-dimensional space exploration, other countries have developed more laser altimeters to enhance their laser exploration capabilities [7][8][9].…”