NDVI时间序列谐波分析法(Harmonic Analysis of NDVI Time-Series)（简称Hants ）对时间序列数据进行平滑。该方法是一种新的物候分析方法，可用于定量化的监测植被动态变化。其核心算法是傅里叶变换和最小二乘法拟合, 即把时间波谱数据分解成许多不同频率的正弦曲线和余弦曲线，从中选取若干个能够反映时间序列特征的曲线进行叠加，以达到时间序列数据的重建目的。(The NDVI Time Series Harmonic Analysis of NDVI Time Series (Hants) smoothes Time Series data. This method is a new phenological analysis method, which can be used for quantitative monitoring of dynamic changes of vegetation. The core algorithm is the Fourier transform and least squares fitting, namely the time spectrum data is decomposed into many different frequency sine curve and cosine curve, selected from several can reflect the characteristics of time sequence curve superposition, the reconstruction of the time series data in order to achieve purpose.)