摘要 |
When a first cable is driven at a locating signal frequency to emit a locating signal, the locating signal can be coupled to a second cable to cause the second cable to generate a false locating signal. As part of discriminating the false signal from the locating signal, the locating signal is generated at the locating signal frequency and phase shifted to produce a phase shifted locating signal frequency. A reference signal is impressed with the phase shifted locating signal frequency. A coupling configuration couples the locating signal frequency onto the first cable to generate the locating signal subject to a coupling configuration phase shift. The phase shifted locating signal, as part of the reference signal, can compensate for the coupling configuration phase shift in the locating signal as emitted by the first cable.
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