Annual large-scale winter crops mapping from MERIS in Russia to prepare Sentinel-2

Crop mapping over large regions is a prerequisite for crop growth monitoring as pointed out in the GEO Report. Crop mapping is now getting operational for lots of different agricultural landscape and regions (GIEWG, MARS, FEWS-NET, GLAM and other national monitoring systems). However, lots of incertitude due to natural phenomena and weather conditions remain. Winter wheat in the Russian Federation (about 10% of the wheat world production) represents one of this incertitude as it subject to winter kill resulting in large yield’s losses. The objectives of this study are (1) to test object based methodologies on temporal medium resolution satellite series in order to map the winter crops in the Russian context and (2) to evaluate the time coverage needed to derive acceptable crop map during the winter crop growing season. The Tula oblast (region of about 26 000 km²) was selected as it is an important winter wheat producer sensible to winter kill. Furthermore, it is located in a relative proximity of Moscow (120 km) allowing field data collection. Field data used for validation and calibration was collected by IKI and AMI for 2 sites containing 10 winter wheat fields for the 2010-2011 growing season.The dataset used in the current study is the Culture-MERIS dataset consisting in averaged bottom-of-atmosphere cloud-free spectral reflectance composites as derived from MERIS FR (300 m.) data acquired globally and processed using the GlobCover production chain. The dataset is available from the 7th March 2011 to 2011 end.