Winter wheat acreage estimation and assessment in China based on FY-3A/MERSI Vegetation Index time series data

FY-3A is a polar-orbiting meteorological satellite launched by China in 2008 which carries Medium Resolution Spectral Imaging (MERSI). This paper used 250m FY-3A/MERSI 10-day composite Normalized Differential Vegetation Index (NDVI) time series to estimate the winter wheat acreage in 10 provinces in northern China. Eleven time series from October 2010 to January 2011 are collected and reconstructed using Savitzky-Golay filter. The study area is divided into five sub regions mainly according to different phonological calendars. About 2 to 3 areas large enough are selected as training samples in every province to produce the winter wheat phenological profile of FY-3A/MERSI/NDVI time series from seeding emergence to overwintering stage. The profiles in different sub regions are then used to study the statistical properties, pattern of winter wheat growth in each region. Some statistic parameters are derived and are then used to develop a regional decision tree classifier for winter wheat seeding area extracting. The classifier accuracy is evaluated to be 87% by the classification result from Landsat TM data. The result based on FY-3A/MERSI time series is also compared with that resulted from MODIS ones, which suggests they are very close in both quantity and distribution. The study proves that FY-3A/MERSI/NDVI time series from seeding emergence to overwintering stage can be used for operational use to estimate winter wheat acreage in northern China.