Schmucker-Weidelt Lecture Notes, Aarhus, 1975 - MTNet

anomalous conductivity oat OP the anomalous conductLvity values
'am
of the blocs m = 1,2,-. .. M, separated by equally spaced
vertical boundaries:
If the search for a best fitting se-t of model parameters is to
be done by an iterative inverse rnethod rather than by trial-and-
error,%inear data kernel matrix G =(g has to be found for
nm
an initial model. In this matrix the element gnm represents the
change yn of the anomalous transfer function at a certain su~face
point and frequency Rn which arises in linear approximation
from a change xm of the model parameter in the m'th bloc of the
starting model. The resulting system of linear equations
- x is solved with the methods of Sec.6. Its solution
Yn
-
m
6nm m
represents the improvement of the initial model, if yn is the
misfit between observed and calculated transfer functions for
the initial model: The process is repeated with the improved
models until the necessary improvements xm are small enough to
justify a linear approximation.
Which complica-tions arise in the general case that not only the
internal conductivity structure but also the inducing source
field are 1aterall.y non-uniform? First of all, in addition to on
as a function of depth the magnetic field H (e) of the external
source must be a known fu11'cti.on of surface location. In the
special case of the equatorial jet field this source field con-
fi.guration w i l l be more or less the same for all day-time varj.a-';iofis
and thus a normalisation.of the observed surface field by the
....