A Rapid Resistivity Profiling Technique Using Code Division Multiple Current Injection

A rapid measurement method for DC resistivity survey is presented. The method uses code division multiple current injection which injects current from plural points simultaneously. Current waveforms are selected as covariance of any pairs of current waveform equal to zero, so that potential response to each current point is easily calculated from potential waveform observed at simultaneous multiple current injection. A result of actual field experiments is demonstrated. A prototype which has 7 current channels and 7 potential channels is developed and tested. Potential response to each current point is separated from observed potential waveform. The apparent resistivity section by the method shows good agreement with that by conventional method.