Phase shifted locating signal as compensation for a coupling configuration phase shift in discriminating a false locating signal
First Claim
1. For use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal can be coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form, as part of an overall procedure for discriminating between the locating signal and the false locating signal, a method, comprising:
- generating said locating signal frequency;
phase shifting the locating signal frequency by a given phase shift to produce a phase shifted locating signal frequency;
producing a reference signal and impressing the phase shifted locating signal frequency thereon, to provide for distinguishing between the locating signal and the false locating signal; and
using a coupling configuration, coupling the locating signal frequency onto the first cable to generate the locating signal in a way which subjects the locating signal frequency to a coupling configuration phase shift such that the phase shifted locating frequency, as part of the reference signal subsequent to a transfer thereof, can compensate for the coupling configuration phase shift of the locating signal frequency in the locating signal as emitted by the first cable.
1 Assignment
0 Petitions
Accused Products
Abstract
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.
33 Citations
11 Claims
-
1. For use in a region which contains at least first and second in-ground cables, each of which cables includes an electrically conductive component such that, when the first cable is driven at a locating signal frequency to emit a locating signal in an electromagnetic form, the locating signal can be coupled to the second cable in a way which causes the second cable to generate a false locating signal in electromagnetic form, as part of an overall procedure for discriminating between the locating signal and the false locating signal, a method, comprising:
-
generating said locating signal frequency; phase shifting the locating signal frequency by a given phase shift to produce a phase shifted locating signal frequency; producing a reference signal and impressing the phase shifted locating signal frequency thereon, to provide for distinguishing between the locating signal and the false locating signal; and using a coupling configuration, coupling the locating signal frequency onto the first cable to generate the locating signal in a way which subjects the locating signal frequency to a coupling configuration phase shift such that the phase shifted locating frequency, as part of the reference signal subsequent to a transfer thereof, can compensate for the coupling configuration phase shift of the locating signal frequency in the locating signal as emitted by the first cable. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification