Abstract: The turbulent signal measured by hot wire is decomposed into three parts with the digital filter and the wavelet analysis. First, the turbulent signal is decomposed into the small scale vortex that has approxmate isotropy and the large scale vortex. Then, the large scale vortex isdecomposed into the coherent and the non coherent parts. Compared with the conditional sampling, the decomposition is realiable. The time scale and non conditional mean profile of coherent structure can be obtained with this meth...