Method for geophysical prospecting using impulsine currents
US4535293A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 26, 1983 |
| Grant date | Aug 13, 1985 |
| Priority date | — |
| Expiry date | Aug 26, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/38
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a method of geophysical prospection a transmitter dipole and a receiver dipole which is sensitive to an electromagnetic field are positioned in cooperation with the subsoil. An impulsive excitation current is applied repeatedly to the transmitter dipole, the excitation current comprising a group of pulses of alternate polarity, each followed by zero current. The transient signal, which is produced thereby at the output of the receiver dipole, is repeatedly detected, and the transient signals are processed to obtain a figurative representation of the transient phenomenon which facilitates geophysical interpretation. Time intervals which are consecutive to excitation pulses and simultaneously with the excitation zero current are defined, these time intervals being of a predetermined duration, chosen to substantially cover all the useful parts of the transient phenomenon. The transient signal is detected as a function of time at least during the time intervals and is sampled, numbered and registered, temporally marked. As used herein, "numbered" may be taken to mean digitalized and "registered" may be taken to mean recorded or memorized. A processing operation is carried out which …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.