Although the filtering method in frequency domain can solve the time variant filtering problem based on Fourier transform, the method may appear a false anomaly in conjunct part between Windows.

频率域滤波方法虽然可解决时变滤波问题，但这种方法是基于傅里叶变换，在窗口与窗口之间的接合部位会出现假异常。

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The reconstruction of flight path is formulated as a discrete, linear, time-variant state reconstruction problem which can be solved by Kalman filtering techniques.

为了得到状态估计的快速算法，本文把非线性飞行轨迹重构转化为线性、离散、时变状态和参数估计问题。

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