Frequency spectrum change of borehole radar signals and blind separation

We model borehole radar signal including a direct wave from a transmitter and a wave reflected from a target by MOM, and we propose a blind separation method to separate the two signals. We modeled the borehole radar signals with MOM, and we will show that power spectrums of a direct wave and reflected waves are different from each other. This can be called a kind of "frequency shift" between the two waves. Making use of these phenomena, we adopted the time-frequency separation (TFS) utilizing the Time-frequency distribution signature as a blind separation technique to separate the two signals. We show experimental results in order to verify the validity of the TFS. We could separated the reflected waves and the direct waves with only 0.4 m depth borehole radar data by the TFS, although the conventional averaged signal subtraction method distorted the reflected waves because of the little depth data.