Header

UZH-Logo

Maintenance Infos

Angular unmixing of photosynthetic and non-photosynethetic vegetation within a coniferous forest using CHRIS-PROBA


Verrelst, J; Zurita-Milla, R; Koetz, B; Clevers, Jan G P W; Schaepman, Michael E (2007). Angular unmixing of photosynthetic and non-photosynethetic vegetation within a coniferous forest using CHRIS-PROBA. In: Int. Symposium on Physical Measurements and Spectral Signature in Remote Sensing, Davos, Switzerland, 12 March 2007 - 14 March 2007, 355-360.

Abstract

Estimating forest variables, such as photosynthetic light use efficiency, from satellite reflectance data requires understanding the contribution of photosynthetic vegetation (PV) and nonphotosynthetic vegetation (NPV). The fractions of PV and NPV present in vegetation reflectance data are typically controlled by the canopy structure and the respective viewing angle. The persistent but highly varying anisotropic behaviour of the forest canopy implies that there is canopy structural information to be exploited from multi-view angles measurements. In this work, a combination of radiative transfer modelling (FLIGHT) and linear unmixing techniques were used to isolate angular PV and NPV fractions from multi-angular CHRIS-PROBA (Compact High Resolution Imaging Spectrometer-Project for On-board Autonomy) data in order to assess their effects on a suite of vegetation indices. Angular variability in the NIR wavelengths contributed most to the angular change in PV and NPV fractions. In turn, for those pixels where the NPV fractions from near-nadir to backscatter were increasing, moderate correlations were found with the angular variability of the calculated vegetation indices. From these fractions, a Normalized Difference NPV Index (NDNPVI) was developed as a proxy for volumetric canopy composition.

Abstract

Estimating forest variables, such as photosynthetic light use efficiency, from satellite reflectance data requires understanding the contribution of photosynthetic vegetation (PV) and nonphotosynthetic vegetation (NPV). The fractions of PV and NPV present in vegetation reflectance data are typically controlled by the canopy structure and the respective viewing angle. The persistent but highly varying anisotropic behaviour of the forest canopy implies that there is canopy structural information to be exploited from multi-view angles measurements. In this work, a combination of radiative transfer modelling (FLIGHT) and linear unmixing techniques were used to isolate angular PV and NPV fractions from multi-angular CHRIS-PROBA (Compact High Resolution Imaging Spectrometer-Project for On-board Autonomy) data in order to assess their effects on a suite of vegetation indices. Angular variability in the NIR wavelengths contributed most to the angular change in PV and NPV fractions. In turn, for those pixels where the NPV fractions from near-nadir to backscatter were increasing, moderate correlations were found with the angular variability of the calculated vegetation indices. From these fractions, a Normalized Difference NPV Index (NDNPVI) was developed as a proxy for volumetric canopy composition.

Statistics

Downloads

26 downloads since deposited on 20 Mar 2013
3 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Conference or Workshop Item (Paper), not refereed, original work
Communities & Collections:07 Faculty of Science > Institute of Geography
Dewey Decimal Classification:910 Geography & travel
Language:English
Event End Date:14 March 2007
Deposited On:20 Mar 2013 16:37
Last Modified:06 Apr 2017 12:17
Publisher:ISPRS
Number:XXXVI-7C50
Free access at:Official URL. An embargo period may apply.
Official URL:http://www.isprs.org/proceedings/XXXVI/7-C50/papers/P49.pdf
Related URLs:http://www.isprs.org/publications/archives.aspx (Publisher)

Download

Preview Icon on Download
Preview
Content: Published Version
Language: English
Filetype: PDF
Size: 7MB