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US 2012/0232837 A1Published application
Enhanced precise location
AssigneeMetrotech Corporation
InventorKun Li
Life of this patent
Estimating the term…
Abstract
A line locator includes a signal detector to detect signals from an underground line; an error modeler that models a phase error in the signal from neighboring underground lines; and an enhanced electromagnetic field modeler that provides a location of the underground line based on the signal and a result from the error modeler.
Claims49
A line locator, comprising:
- a plurality of coil detectors, each of the plurality of coil detectors oriented to measure a component of an electromagnetic field;
- circuitry coupled to provide quadrature signals indicating a complex electromagnetic field strength;
- a position locator for indicating a position of the line locator;
- a processor coupled to receive the complex electromagnetic field strength and the position, and to calculate values related to a target line, wherein
- the processor is configured to execute instructions for:
- modeling an expected complex field strength using a phase error function, and using an estimation of a current attenuation at two nearest side tones to update a fit factor, the side tones defined by a carrier frequency and a modulation frequency;
- and
- determining parameters related to the target line from a best model.
5 more elements
A method of locating a target line, comprising:
- measuring an electromagnetic field using a plurality of coil detectors;
- modeling a phase error based on the presence of lines neighboring the target line, wherein modeling comprises using a phase error function including a plurality of parameters from the target line and from the neighboring lines, and an estimation of a current attenuation at two nearest side tones to update a fit factor, the side tones defined by a carrier frequency and a modulation frequency;
- and
- utilizing the phase error in an enhanced electromagnetic field model to locate the target line.
1 more element
Dependencies are inferred from the claim text.