In: Wagner W., Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B
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computational adaptation of the original SWI algorithm has
been made based on a recursive formulation proposed by
Albergel (2008). In this method, a gain factor is introduced that
relates the past SWI measurements to the current
measurements. The SWI processing algorithm uses ASCAT-
25km Level 2 Soil Surface Moisture product as input to
generate daily global SWI images, calculated for 8 different T
values (1, 5, 10, 15, 20, 40, 60, 100) together with the
respective quality flags.
The product has the following characteristics (see the PUM
document on SDI for more details) : index values quality flags,
spatial resolution 25 km, temporal resolution 1 day, geometric
accuracy 4 km, thematic target accuracy 10%, global coverage.
January 2009 Time length = 10
July 2009 Time length = 10
July 2009 Time length = 40
July 2009 Time length = 100
Figure 6 : Soil Water Index data sets, © CNES/TU Wien.
4. CONCLUSION
These first deliveries of BioPar test data show that vegetation
and humidity variables products are know qualified and
available for end users analysis. The product lines shall be
operational for NRT processing in the production centres
(VITO & IM) before the end of the year. All the products are
available on the SDI web portal.
Development will continue on the same scheme and new
versions are foreseen :
• Version 2 of vegetation variable processing line will
improve the overall performance of the product line
by applying directly the neural network to the VGT-P
top of atmosphere reflectance. Products shall be
available end of 2011.
• SWI & F/T Version 2 will improve the detection of
ffeeze/thaw surface conditions and shall be available
beginning of 2012.
CNES participate also to the SATChMo Core Monitoring
Service (see figure 1) and will deliver end of 2011 a medium
resolution land cover change map from MODIS data, on
Europe and Africa. The development activities, shared with
Université Catholique de Louvain in Belgium and the Institute
of Geodesy and Cartography in Poland, will follow the same
engineering cycle that BioPar.
5. REFERENCES
[1] Lacaze R. & al., Geoland2 - Towards an operational GMES
Land Monitoring Core Service; First Results of the
Biogeophysical Parameter Core Mapping Service, ISPRS 2010
[2] Baret, F., Hagolle, O. et ah, 2007. LAI, fAPAR and fCover
CYCLOPES global products derived from VEGETATION.
Part 1: Principles of the algorithm. Rem. Sens. Environ., 110:
275-286.
[3] Weiss, M., Baret, F., Garrigues, S., Lacaze, R. and
Bicheron, P., 2007. LAI, fAPAR and fCover CYCLOPES
global products derived from VEGETATION, part 2:
Validation and comparison with MODIS Collection 4 products.
Rem. Sens. Environ, 110: 317-331.
[4] Albergel, C., Rüdiger, C., Pellarin, T., Calvet, J.-C., Fritz,
N., Froissard, F., Suquia, D., Petitpa, A., Piguet, B., Martin,
E., 2008. From near-surface to root-zone soil moisture using an
exponential filter: an assessment of the method based on in-
situ observations and model simulations. Hydrol. Earth Syst.
Sei. 12: 1323-1337.
[5] Wagner, W., Lemoine, G., Rott, H., 1999. A Method for
Estimating Soil Moisture from ERS Scatterometer and Soil
Data. Rem. Sens. Environ. 70: 191-207.
6. WEBSITES
Geoland 2 : http://www.land.eu
SDI portal : http://www.geoland2.eu/
POSTEL : Land surface thematic centre,
http ://postel. mediasfrance.org/
CNES : http://www.cnes.fr
VEGA Technologies : http://www.vegatechnologies.fr