Patent ID: 8400157
Filing Date: 2013-03-19
Classification: G01V

Abstract:
1. A time domain electromagnetic (TDEM) geophysical survey system for producing a B-field measurement, comprising: (a) a transmitter coil; (b) a semi-rigid bucking coil positioned in a substantially concentric and coplanar orientation relative to the transmitter coil; (c) a receiver coil positioned in a substantially concentric and coplanar orientation relative to the bucking coil; (d) an electrical current source connected to the transmitter coil and bucking coil for applying a periodic current thereto; the transmitter coil, bucking coil and receiver coil being positioned relative to each other such that, at the location of the receiver coil, a magnetic field generated by the bucking coil has a cancelling effect on a primary magnetic field generated by the transmitter coil; and (e) a data collection system configured to receive a magnetic field time-derivative signal dB/dt from the receiver coil and integrate the magnetic field time derivative signal dB/dt to generate a magnetic B-field measurement.