Abstract: A new time-frequency signal analysis method, Rihaczek distribution, based on local correlation distribution of signal energy between time and frequency domains is proposed. The distribution has an evident physical significance. This method was provided with the abilities to distinguish and identify different kinds of lithologies and structural responses. And the Rihaczek distributions of array acoustic logging signal have evident differences for different rocks and structural fractures zones. Using the corresponding pattern recognition method, the lithologies and structures can be distinguished and identified effectively.

Key words: array acoustic logging, time-frequency distribution, signal analysis, Rihaczek distribution