Mapping Bedrock lithology in urban environment via large scale time domain induced polarization tomography

The present work is an example of a Direct-Current resistivity and time-domain Induced Polarization (DCIP) survey, carried out in an urban environment. The main goal of the survey is to map a weak zone in the bedrock, through which a tunnel will be constructed. Geophysical measurements in urban environments can be very complicated due to the restrictions of available space and the high levels of noise. A way to deal with the latter is careful processing of the recorded waveforms, if they are sampled at a reasonably high frequency (sampling = 1 KHz). A deeper understanding of raw data leads to a more accurate use of the measured quantities, improving the reliability of electrical resistivity and IP estimations