US 2014/0368196 A1 · PRACTICAL ELECTROMAGNETIC GRADIOMETER

Abstract

An electromagnetic gradiometer (EMG) survey kit includes a lightweight man-carry boom about ten feet long. Matched magnetic dipole antennas are attached at each end and connected to a differential EMG receiver able to make measurements in the picoTelsa range. A pair of staging tripods allow the man-carry boom to be prepared for field use and assist the user in positioning themselves under a shoulder sling. An air core transmitter loop antenna and a low frequency square wave generator are spotted nearby a survey on the ground surface. Its emissions will illuminate any underground conductive structures with primary electric field waves. These in turn will reradiate near field magnetic waves that can be detected by the EMG receiver while walking around in a search area on the ground surface. GPS navigation receivers are used to locate and log the changing positions of the EMG receiver and stationary loop transmitter.

Claims13

Dependent claims

A mobile electromagnetic gradiometer (EMG) receiver, comprising:

a man-carry boom about ten feet long and including pipe fittings for the rigid mounting of antennas;
a differential EMG receiver for taking magnetic field measurements in the picoTelsa range, and mounted off center on the man-carry boom;
a matched pair of magnetic dipole antennas mechanically attached and rigidly supported at each end of the man-carry boom, and each electrically connected to a respective input of the differential EMG receiver;
and
an output device mounted on the man-carry boom to visually display to a user the relative locations and characters of underground conductor targets as interpreted from magnetic field measurements collected by the differential EMG receiver.

2 more elements

An electromagnetic gradiometer (EMG) survey kit, comprising:

a man-carry boom about ten feet long and including supporting mounts for a receiver and pipe fittings for rigid mounting of antennas;
a pair of staging tripods for supporting the man-carry boom when not in use, and for facilitating assembly, disassembly, and configuration changes to the man-carry boom;
a differential EMG receiver (Rx) for making magnetic field measurements in the picoTelsa range, and mounted to the man-carry boom;
a plurality of matched pairs of magnetic dipole antennas for attachment by said pipe fittings one pair at a time at each end of the man-carry boom, and including electrical connectors for inputs to the differential EMG receiver (Rx), wherein each pair of magnetic dipole antennas is designated for and constructed to operate at different fixed frequencies;
at least one air-core transmitter (Tx) loop antenna designated for and constructed to operate at different fixed frequencies, and single transmitter controller for driving all such Tx loop antennas at selected ones of the different fixed frequencies, and independent and apart from the differential EMG receiver (Rx);
and
an output device mounted on the man-carry boom to visually display to a user the relative locations and characters of underground conductor targets as interpreted from magnetic field measurements collected by the differential EMG receiver (Rx).

4 more elements

Dependencies are inferred from the claim text.

Practical electromagnetic gradiometer

Life of this patent

Practical electromagnetic gradiometer

Life of this patent

Abstract

Claims13