@article{fdi:010068278,
  title = {{I}nterpretation of magnetic resonance measurements in the varying earth's magnetic field},
  author = {{L}egchenko, {A}natoli and {V}ouillamoz, {J}ean-{M}ichel and {L}awson, {F}. {M}. {A}. and {A}lle, {C}. and {D}escloitres, {M}arc and {B}oucher, {M}arie},
  editor = {},
  language = {{ENG}},
  abstract = {{A}t the scale of a magnetic resonance sounding ({MRS}) field setup, the earth's magnetic field in the subsurface may vary laterally with depth and over time. {T}hese variations can be caused by different natural factors and generally cannot be compensated for by accurate tuning of the measuring device. {T}he varying geomagnetic field ({GMF}) causes nonresonance conditions of excitation that affect the amplitude and phase of the {MRS} signal. {U}sually, variations of the {GMF} do not exceed a few hertz and their effect on the amplitude is relatively small, permitting us to assume near-resonance conditions for inversion. {H}owever, in some cases, the results may be erroneous if a varying {GMF} is not taken into account. {M}otivated by possible improvements in {MRS} inversion, we have developed a procedure for measuring and interpreting {MRS} data that considers a varying {GMF}. {O}ur results showed that it is relatively easy to take a time-varying {GMF} into account. {A}s a demonstration, we have developed the inversion of {MRS} data measured in {B}enin ({W}est {A}frica). {A} depth-varying {GMF} is a more complex problem, and to consider this, we have developed an algorithm of nonlinear inversion. {W}e have tested this approach on synthetic data, which resulted in an improved inversion. {F}ield validation of this procedure awaits the discovery of a suitable test site with known variations of the earth's magnetic field in the subsurface.},
  keywords = {{BENIN}},
  booktitle = {},
  journal = {{G}eophysics},
  volume = {81},
  numero = {4},
  pages = {{WB}23--{WB}31},
  ISSN = {0016-8033},
  year = {2016},
  DOI = {10.1190/geo2015-0474.1},
  URL = {https://www.documentation.ird.fr/hor/fdi:010068278},
}