Definitions for MT Transfer Functions and Derived Quantities

MT Impedance Ellipticity: ZELLIP

The impedance ellipticity is usually defined as:

ZELLIP=\frac{|(Z_{xx}-Z_{yy})*cos(2A)+(Z_{xy}+Z_{yx})*sin(2A)|}{|(Z_{xy}+Z_{yx})*cos(2A)+(Z_{xx}-Z_{yy})*sin(2A)|}

where Zxx, Zyy, Zxy, Zyx - are 4 components of impedance tenzor, and A is the calculated impedance principal direction.

References

Chave, A.D. and Jones, A.G. eds., 2012. The magnetotelluric method: Theory and practice. Cambridge University Press.
Wight, D.E., 1987. Society of Exploration Geophysicists MT/EMAP Data Interchange Standard.