Bucking circuit for annulling a magnetic field
US9297922B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 23, 2013 |
| Grant date | Mar 29, 2016 |
| Priority date | — |
| Expiry date | Feb 8, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus is provided for bucking a magnetic field of known geometry and time variation by means of a plurality of bucking loops. It utilizes multiple loops, each of which is energized by an electric current that creates a magnetic field of the known time variation. The multi-loop field forms a bucking magnetic field that better opposes the spatial variation in the known magnetic field over a volume than can the magnetic field from a single loop. The present invention is useful in electromagnetic measurements, where the magnetic field of a controlled source transmitter must be annulled at a magnetic field sensor. It is particularly useful for cases where the magnetic sensor may move relative to the transmitter, such as in certain airborne electromagnetic measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.