动态Allan方差（DAVAR）法是分析非平稳性信号的有效工具，窗函数选取固定使得在辨识噪声时存在功率泄漏和定量单一的缺陷。为此，提出了一种以σ2比值法（F值）为判据标准，自适应调整窗口长度的DAVAR改进算法。首先用F值反映随机信号的突变特征，进而根据实时变化的F值计算窗函数的长度，并且自动对信号进行截取，最终将所计算的DAVAR绘制在三维图形内。对实际采集的陀螺仪随机信号的分析表明，该方法能准确反映动态噪声的变化特征，保证实时的突变跟踪能力和良好的置信度，为研究在各种干扰因素下陀螺仪组成的IMU误差建模与补偿提供了理论参考和评价依据。

Dynamic Allan Variance（DAVAR）is an effective tool for the analysis of non-stationary signal.Since the window function is selected fixed, it has the defects of power leakage and single quantity in the identification of noise.Thus we put forward an improved DAVAR algorithm based on adaptive sliding window taking σ2 ratio (F value) as the criteria.Firstly, the F value is used to reflect the mutation characteristics of stochastic signal.Then, the length of the window function is calculated out according to the real-time change of F value, and stochastic signal is intercepted automatically.Finally, the piecewise Allan value is drawn on 3-D graphics.Analysis is made to the collected gyroscope signal.The result shows that the method can accurately reflect the change of dynamic noise characteristics, and ensure implementation of mutation tracking ability and good degree of confidence, which provides a theoretical reference for the study of inertial navigation system composed by gyroscopes under interference factors.