Underground, time domain, electromagnetic reflectometry for digging apparatus
US4006481A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 1975 |
| Grant date | Feb 1, 1977 |
| Priority date | — |
| Expiry date | Dec 10, 1995 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01Q13/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for detecting the presence of a buried, hidden object in the vicinity of a digging tool in order to prevent a human disaster and damage to utility lines or other buried structures. The apparatus includes an impulse generator and data processing means connected to a slot antenna formed in the tool of an earthmoving machine for radiating a burst of broad spectrum electromagnetic energy into the ground and for receiving and data processing reflected electromagnetic echoes. One antenna embodying the invention comprises a slot formed through a wall of a hydraulically driven shovel and filled with a ceramic absorber. The slot has four radially extending, orthogonally arranged loops having unclosed central portions of the loops joined end to end to form four apexes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.