| 摘要 |
This is solved according to the invention by one or more features. In one aspect, by a method for mapping a geological structure in a formation on one side of a surface, and comprising a sequence lasting a sequence period and comprising at least one moment period with: - an on-period where a magnetic field is built up in the said formation by generating a magnetic moment, which magnetic moment has a moment strength, using at least one magnetic moment generator, which is positioned on the other side of the surface at a given position, which on-period is separated from an off-period by a step where - the magnetic field is brought to change by changing the magnetic moment, and where - the off-period where at a recording time t record in a recording device at least one record is made, which record includes at least: - a representation of the change in the magnetic field and/or - a representation of the magnetic field obtained by a B/E-measuring unit, and where at least two sequences are performed where each sequence is performed with different absolute values of moment strengths of magnetic moments and/or different on-time periods of magnetic moments and that the duration of the said least two sequences is less than 1 second. |
