Identification and mapping of underground facilities
US7928892B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 7, 2008 |
| Grant date | Apr 19, 2011 |
| Priority date | — |
| Expiry date | Jul 5, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q15/0086
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system or method of creating a map of voids in the ground based on a scattered electromagnetic signal includes traversing a receiver/probe in a near field above a target area; generating a signal from a signal transmitter, the signal having a predetermined wavelength λ; receiving a scattered signal with the receiver/probe, the scattered signal including indications of subsurface variations via reflection of the generated signal; and detecting evanescent components of the scattered signal to provide a predetermined resolution. The method includes the use of an electrically small antenna for resolution of subwavelength features. The metamaterial-based antenna is on the order of meters and has an efficient transmit/receive capability. The ESA is 1/10 of the length of the equivalent dipole length, and may be scaled down to 1/10,000. Such an antenna may include phase sensitive current injection in the metamaterial resonant structures for loss-compensation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.