Journal article

Intercomparison of clumping index estimates from POLDER, MODIS, and MISR satellite data over reference sites

Jan Pisek, Ajit Govind, Stefan K Arndt, Darren Hocking, Timothy J Wardlaw, Hongliang Fang, Giorgio Matteucci, Bernard Longdoz



Clumping index is the measure of foliage grouping relative to a random distribution of leaves in space. It is a key structural parameter of plant canopies that influences canopy radiation regimes and controls canopy photosynthesis and other land-atmosphere interactions. The Normalized Difference between Hotspot and Darkspot (NDHD) index has been previously used to retrieve global clumping index maps from POLarization and Directionality of the Earth's Reflectances (POLDER) data at ~6. km resolution and the Bidirectional Reflectance Distribution Function (BRDF) product from Moderate Resolution Imaging Spectroradiometer (MODIS) at 500. m resolution. Most recently the algorithm was also applied ..

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University of Melbourne Researchers


Awarded by FP7-Marie Curie Actions programme, Estonian Science Foundation

Awarded by Australian Research Council (ARC)

Awarded by National Natural Science Foundation of China

Funding Acknowledgements

Jan Pisek was supported by the funding from the FP7-Marie Curie Actions programme, Estonian Science Foundation Grant nos. ERMOS32 and PUT232. Financial support by the Transnational Access to Research Infrastructures activity in the 7th Framework Programme of the EC under the ExpeER project for conducting the research at Castelporziano and Hesse sites is gratefully acknowledged. The measurements at Wombat, Whroo and Warra in Australia were funded by the Terrestrial Ecosystem Research Network (TERN) Australian Supersite Network, the TERN OzFlux Network, and Australian Research Council (ARC) Grants LE0882936 and DP120101735. Data collection at the Honghe farm was supported by the National Natural Science Foundation of China (41171333). The first author would like to thank Drs. Lola Suarez and Zbynek Malenovsky for their help with transport logistics to Wombat and Whroo sites. We thank two anonymous reviewers for providing comments that helped with improving quality of the original submission. Research and access at the Castelporziano site was granted by the Scientific-Technical Commission (STC) of the Reserve. Activities at the Grotte di Piastra flux tower are partly funded by the STC and are performed in cooperation by CNR, CRA and University of Tuscia. The General Secretariat of the Presidency of the Italian Republic is greatly acknowledged.