Publications

Raymaekers, D.; Garcia, A.; Di Bella, C.; Beget, M. E.; Llavallol, C.; Oricchio, P.; Straschnoy, J.; Weiss, M.; Baret, F. (2014). SPOT-VEGETATION GEOV1 biophysical parameters in semi-arid agro-ecosystems. INTERNATIONAL JOURNAL OF REMOTE SENSING, 35(7), 2534-2547.

Abstract
The VEGETATION system, which has been delivering global observations of the surface on a daily basis since 1998, provides key information for regional to global climate, environmental and natural resource management applications. Just recently, VEGETATION-derived GEOV1 biophysical products (LAI, FAPAR, and FCOVER) became available for the scientific community and were evaluated in this study for semi-arid forests in the Dry Chaco ecoregion, Argentina. Indirect validation with the MODIS-derived biophysical products (MOD15A2) shows a very good temporal consistency between both products for the period 2000-2011, with a remarkably smooth behaviour of the GEOV1 products. A good relationship between both products was found in the regression analysis with an R-2 of 0.826 and 0.724 for LAI and FAPAR, respectively. Using direct validation with digital hemispherical photography (DHP) and ceptometer ground measurements, a relatively small RMSE (RMSELAI approximate to 0.31 and RMSEFAPAR approximate to 0.11) was found. The novel PASTIS-57 technique, which can derive continuous plant area index (PAI) estimates from light transmittance measurements, shows a similar temporal profile to the GEOV1 LAI product with a relatively high but constant offset for the dry forest study sites and a nearly identical profile for the deforested site (R-2=0.86). Overall, PASTIS-57, in combination with satellite-based observations, shows potentials in LAI/PAI research and ecosystem carbon studies in general, but more ground measurements taken over multiple growing seasons and vegetation types are required to confirm these findings.

DOI:
10.1080/01431161.2014.883096

ISSN:
0143-1161; 1366-5901