Method and apparatus for locating buried conveyances using locating & confirmation signals with an array of sensors
US5798644A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 20, 1997 |
| Grant date | Aug 25, 1998 |
| Priority date | — |
| Expiry date | Feb 20, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/15
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Precise location of a buried utility conveyance (10) is achieved by impressing on the conveyance low frequency conveyance-locating and conveyance confirmation signals, the later being pulsed in a particular pattern unique to the conveyance to be located. A first sensor (22) detects a first magnetic field radiated by the conveyance upon receipt of the conveyance-locating signal. An array (24) of sensors (26.sub.1 -26.sub.5) detects the second magnetic field radiated by the conveyance upon receipt of the conveyance-confirmation signal. A processor (32) coupled to the sensors (26.sub.1 -26.sub.5) precisely vectors the location of the conveyance from the second magnetic field strength sensed by each sensor (26.sub.1 -26.sub.5).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.