A new time-frequency detection method of stray current field interference on metal structures

A new detection method has been presented of stray current field interference on underground metal structures. The method employs short time Fourier transformation (STFT). This method of analysis allows determination of signal spectral power density changes (e.g., structure potential) in the function of time. In the paper results have been presented of total time-frequency analysis of a pipeline potential in a stray current field generated by a tram traction. The presented results have unequivocally shown that the described method allows accurate identification of the stray current source and determination if it interacts with the underground metal structure. (C) 2003 Elsevier Ltd. All rights reserved.