Tracking positions of personnel, vehicles, and inanimate objects
US7425829B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 7, 2004 |
| Grant date | Sep 16, 2008 |
| Priority date | — |
| Expiry date | Mar 16, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A device rotates at least one static magnetic field about an axis, producing a rotating magnetic dipole field, and is movable in relation to the surface of the ground. The field is periodically sensed using a receiver to produce a receiver output responsive to the field. A positional relationship between the receiver and the device is monitored using the output. In one aspect, changing the positional relationship, by moving the device nearer to a boring tool which supports the receiver, causes an increase in accuracy of depth determination. In another aspect, determination of an actual overhead position of the boring tool, and its application, are described. Use of a plurality of measurements over at least one-half revolution of each magnet is disclosed. Establishing a surface radial direction toward a boring tool and resolution of multi-valued parameters is described. Calibration techniques, as well as a three transmitter configuration are also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.