Electromagnetic method for locating underground anomalies

Patent · Mon Sep 12 04:00:00 EDT 1977

OSTI ID:6697003

Lytle, R J; Laine, E F; Lager, D L; Davis, D T

Underground anomalies or discontinuities, such as holes, tunnels, and caverns, are located by lowering an electromagnetic signal transmitting antenna down one borehole and a receiving antenna down another, the ground to be surveyed for anomalies being situated between the boreholes. Electronic transmitting and receiving equipment associated with the antennas is activated and the antennas are lowered in unison at the same rate down their respective boreholes a plurality of times, each time with the receiving antenna at a different level with respect to the transmitting antenna. The transmitted electromagnetic waves diffract at each edge of an anomaly. This causes minimal signal reception at the receiving antenna. Triangulation of the straight lines between the antennas for the depths at which the signal minimums are detected precisely locates the anomaly. Alternatively, phase shifts of the transmitted waves may be detected to locate an anomaly, the phase shift being distinctive for the waves directed at the anomaly.

• Assignee: Department of Energy
• Patent Number(s): None
• OSTI ID: 6697003
• Country of Publication: United States
• Language: English

Related Subjects

15 GEOTHERMAL ENERGY
150301 -- Geothermal Exploration & Exploration Technology-- Geophysical Techniques & Surveys
58 GEOSCIENCES
580203* -- Geophysics-- Geophysical Survey Methods-- (1980-1989)
ANTENNAS
BOREHOLES
CAVITIES
COHERENT SCATTERING
DIFFRACTION
ELECTRICAL EQUIPMENT
ELECTRICAL SURVEYS
ELECTROMAGNETIC RADIATION
ELECTROMAGNETIC SURVEYS
EQUIPMENT
GEOPHYSICAL SURVEYS
LEVELS
MEASURING METHODS
RADIATIONS
SCATTERING
UNDERGROUND