Stage 1 Validation of Plant Area Index from the Global Ecosystem Dynamics Investigation

Brown, Luke A.; Morris, Harry; Meier, Courtney; Knohl, Alexander; Lanconelli, Christian; Gobron, Nadine; Dash, Jadunandan; Danson, F. Mark

Abstract

The Global Ecosystem Dynamics Investigation (GEDI) aims to provide improved characterization of forest structure, and plant area index (PAI) is one of many variables provided in the official GEDI Level 2B (L2B) product suite. However, since release, few quantitative validation studies have been conducted. To reach Stage 1 of the validation hierarchy proposed by the Land Product Validation (LPV) sub-group of the Committee on Earth Observation Satellites (CEOS) Working Group on Calibration and Validation (WGCV), we provide an initial assessment of PAI estimates from GEDI’s L2B product. This is achieved using 18 in situ reference measurements available through the Copernicus Ground Based Observations for Validation (GBOV) service. We show that GEDI L2B PAI retrievals provide a nearly unbiased estimate of effective (PAI e ) (RMSD = 0.95, bias = 0.02, slope = 1.07), but systematically underestimate PAI (RMSD = 1.42, bias = -0.91, slope = 0.77). This is attributed to an assumed random distribution of plant material in the algorithm. To reach Stage 2 of the CEOS WGCV LPV hierarchy, continued work is needed to validate the product against additional in situ reference measurements covering further locations and time periods.

Citation

Brown, L. A., Morris, H., Meier, C., Knohl, A., Lanconelli, C., Gobron, N., …Danson, F. M. (2023). Stage 1 Validation of Plant Area Index from the Global Ecosystem Dynamics Investigation. IEEE Geoscience and Remote Sensing Letters, 1-1. https://doi.org/10.1109/lgrs.2023.3319528

• Journal Article Type: Article
• Acceptance Date: Sep 21, 2023
• Online Publication Date: Sep 26, 2023
• Publication Date: Oct 6, 2023
• Deposit Date: Sep 28, 2023
• Publicly Available Date: Sep 29, 2023
• Journal: IEEE Geoscience and Remote Sensing Letters
• Print ISSN: 1545-598X
• Publisher: Institute of Electrical and Electronics Engineers
• Peer Reviewed: Peer Reviewed
• Pages: 1-1
• DOI: https://doi.org/10.1109/lgrs.2023.3319528
• Keywords: Electrical and Electronic Engineering, Geotechnical Engineering and Engineering Geology