Tang, L; Zhao, ZM; Tang, P; Yang, HJ (2020). SURE-based optimum-length S-G filter to reconstruct NDVI time series iteratively with outliers removal. INTERNATIONAL JOURNAL OF WAVELETS MULTIRESOLUTION AND INFORMATION PROCESSING, 18(2), 2050001.

Savitzky-Golay (S-G) filter is a method of local polynomial regression, and iterative filtering with S-G filter can be used to smooth out random noise and outliers of cloud noise in NDVI time series. It involves a continuous approximation to the upper envelope of NDVI time series. In this paper, the optimum-length of S-G filter was estimated based on Steinc's unbiased risk estimator theory when S-G filtering was conducted iteratively, and the reconstruction result was presented. Reconstruction experiments on the simulated data and MODIS NDVI time series of the year 2010-2014 showed that the optimum-length S-G filter can outperform the fixed bandwidth S-G filter.