The University of Southampton
University of Southampton Institutional Repository

Estimation of leaf area index from PROBA/CHRIS hyperspectral multi-angular data

Estimation of leaf area index from PROBA/CHRIS hyperspectral multi-angular data
Estimation of leaf area index from PROBA/CHRIS hyperspectral multi-angular data
Leaf Area Index (LAI) is a key structural and functional biophysical variable of the vegetated surfaces which is important in quantifying evapotranspiration rates and the energy exchange of terrestrial vegetation. Remote sensing offers a method of providing estimates of LAI through the analysis of the Bidirectional Reflectance Distribution Function (BRDF), an angular-dependent surface response. High-resolution, multi-angular and hyperspectral image data from PROBA/CHRIS (Project On-Board Autonomy/ Compact High Resolution Imaging Spectrometer) are used to estimate LAI. The retrieval of LAI is accomplished using the 1D turbid-medium canopy reflectance model, SAIL, coupled with the leaf reflectance model, PROSPECT REDUX. Look-up-tables are generated using scene-specific parameters required to invert the physically based model. Two experiments are performed to examine the contribution of multispectral versus hyperspectral reflectances (nadir direction) and single-look versus multi-look hyperspectral reflectances in deriving the LAI. Image data of the calibration/validation site at Chilbolton, Hampshire, UK are used for the inversion. In addition, ground measurements of LAI are compared with the retrieved LAI estimates. Retrieved LAI estimates using various spectral and directional sampling suggest that the spectro-directional reflectances from CHRIS provides more accurate results than their lower-resolution counterparts such as single-look and multispectral reflectances.
lai, chris, lut, hyperspectral, sail
1-4
Remote Sensing and Photogrammetry Society
Kamalesh, V.L.
6ea368e7-6902-4e73-9c9c-9270b0e292c2
Luckman, A.
964eae91-8877-466b-b230-63a418effbfe
Grey, W.M.F.
498b9257-03b7-45b1-9a99-4adb49c450fb
Milton, E.J.
f6cb5c0d-a5d4-47d7-860f-096de08e0c24
Kamalesh, V.L.
6ea368e7-6902-4e73-9c9c-9270b0e292c2
Luckman, A.
964eae91-8877-466b-b230-63a418effbfe
Grey, W.M.F.
498b9257-03b7-45b1-9a99-4adb49c450fb
Milton, E.J.
f6cb5c0d-a5d4-47d7-860f-096de08e0c24

Kamalesh, V.L., Luckman, A., Grey, W.M.F. and Milton, E.J. (2008) Estimation of leaf area index from PROBA/CHRIS hyperspectral multi-angular data. In Proceedings of the Remote Sensing and Photogrammetry Society Conference: “Measuring Change in the Earth System”. University of Exeter, 15-17 September 2008. Remote Sensing and Photogrammetry Society. pp. 1-4 .

Record type: Conference or Workshop Item (Paper)

Abstract

Leaf Area Index (LAI) is a key structural and functional biophysical variable of the vegetated surfaces which is important in quantifying evapotranspiration rates and the energy exchange of terrestrial vegetation. Remote sensing offers a method of providing estimates of LAI through the analysis of the Bidirectional Reflectance Distribution Function (BRDF), an angular-dependent surface response. High-resolution, multi-angular and hyperspectral image data from PROBA/CHRIS (Project On-Board Autonomy/ Compact High Resolution Imaging Spectrometer) are used to estimate LAI. The retrieval of LAI is accomplished using the 1D turbid-medium canopy reflectance model, SAIL, coupled with the leaf reflectance model, PROSPECT REDUX. Look-up-tables are generated using scene-specific parameters required to invert the physically based model. Two experiments are performed to examine the contribution of multispectral versus hyperspectral reflectances (nadir direction) and single-look versus multi-look hyperspectral reflectances in deriving the LAI. Image data of the calibration/validation site at Chilbolton, Hampshire, UK are used for the inversion. In addition, ground measurements of LAI are compared with the retrieved LAI estimates. Retrieved LAI estimates using various spectral and directional sampling suggest that the spectro-directional reflectances from CHRIS provides more accurate results than their lower-resolution counterparts such as single-look and multispectral reflectances.

Text
90_RSPSoc_paper_2008_VKamalesh.pdf - Version of Record
Download (403kB)

More information

Published date: 15 September 2008
Venue - Dates: Remote Sensing and Photogrammetry Society Conference: “Measuring Change in the Earth System”, Exeter, United Kingdom, 2008-09-15 - 2008-09-17
Keywords: lai, chris, lut, hyperspectral, sail

Identifiers

Local EPrints ID: 63466
URI: http://eprints.soton.ac.uk/id/eprint/63466
PURE UUID: 4b3e797d-0f06-42dc-9f58-c0d2c559a0d0

Catalogue record

Date deposited: 09 Oct 2008
Last modified: 15 Mar 2024 11:40

Export record

Contributors

Author: V.L. Kamalesh
Author: A. Luckman
Author: W.M.F. Grey
Author: E.J. Milton

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×