Comparison of Satellite and Ground-Based Phenology in China’s Temperate Monsoon Area

Table 2

Summary of five methods in estimating SOS from satellite data. The number for each method is defined for the purpose of distinguishing the satellite-derived SOS measures from ground phenophases in Table 1.

No.	Methods	Curve approaches	SOS determination approaches	Reference
13	Polyfit	Polynomial function	Threshold by the timing of greatest relative change in multi-year averaged series	[17]
14	Logistic	Piecewise logistic functions	Maximum relative change	[24]
15	HANTS	Fourier transformation	Maximum increase	[33]
16	Midpoint	Spline functions	Midpoint	[27]
17	Timesat	Savitzky-Golay filter	20% of NDVI amplitude	[28]