Retrieval of Cropping Index in China Using Time Series of SPOT Vegetation NDVI

The Multicropping index is a very important statistical index and has been widely used in agricultural production management in China. The Multicropping index indicates the situation and intensity of arable land to be used by a certain planting system at time scale. Monitoring the crop profile in one year with time series of NDVI may help calculate the multicropping index. Time series of NDVI has been successfully used to retrieve the biophysical processes of planting, seedling, elongating, heading, harvesting of agricultural crops. The Multicropping index is equal to the number of the curve peaks of time series of NDVI in the period of one year. Harmonic Analysis of NDVI Time Series (HANTS) was used to smooth and reconstruct time series of NDVI and an algorithm for calculating the number of peaks was developed in this study. The paper presented the remote sensing technique for extracting the multicropping index and then mapped the multicropping index using 4 year SPOT-VEGETATION decadal composite time series of NDVI from 1999 to 2002. The validation results indicated high accuracy in comparison with 4 sites ground data and TM data retrievals.