Evaluation of phenology extracting methods from vegetation index time series

This paper evaluated the extraction rate and accuracy of 5 phenology extracting method, taking the vegetation phenological metrics derived from the net ecosystem carbon exchange (NEE) data of 72 flux towers in North America as the reference data. The results indicated that the local midpoint method achieved the highest extraction rate and accuracy. Better performance was observed for the moving average method and the polynomial function fitting method. However, the extraction rate and accuracy of the moving average method were sensitive to the moving window size. The global threshold method performed quite poor. The phenological metrics extracted with the piecewise Logistic function fitting method had a large systematic discrepancy with the NEE derived phenological metrics but there was a strong correlation between them, which indicated that the vegetation phenological metrics extracted with the piecewise Logistic function fitting method can reflect the temporal and spatial variation of vegetation phenology.