3.3.2. Predicted Data File¶
The predicted data file is output from e3dMTfwd.exe and contains the locations and predicted data. The order of the data point is in the same order as the survey and locations file. Each block, separated by a blank line, are the data for a particular transmitter and frequency. Thus predicted data files take the format:
3.3.2.1. MT data (DATATYPE = MTZ)¶
Each row in the array contains the elements of the impedance tensor at a particular location separated into real and imaginary components. The units for predicted MT data are (V/A). The columns for this data format are as follows:
where
The data location is given by Easting, Northing and Elevation in metres
\(Z^\prime_{ij}\) is the real component of entry i,j of the impedance tensor
\(Z^{\prime\prime}_{ij}\) is the imaginary component of entry i,j of the impedance tensor
Important
For standard MT data, X = Northing, Y = Easting and Z = Down; which this code uses! Thus \(Z_{xy}\) is essentially the ratio of the electric field along the Northing and the magnetic field along the Easting. For more, see the theory section.
3.3.2.2. ZTEM data (DATATYPE = MTT, MTE or MTH)¶
Each row in the array contains the elements of the transfer function at a particular location separated into real and imaginary components. Predicted ZTEM data are unitless with no normalization factor. The columns for this data format are as follows:
where
The data location is given by Easting, Northing and Elevation in metres
\(T^\prime_{zx}\) is the real component of \(T_{zx}\)
\(T^{\prime\prime}_{zx}\) is the imaginary component of \(T_{zx}\)
and similarly for \(y\).
Important
For standard natural source data, X = Northing, Y = Easting and Z = Down; which this code uses! Thus \(T_{zx}\) is the transfer function related to an incident plane wave whose electric field is polarized along the Northing direction; which produces magnetic fields with components in the Easting direction. For more, see the theory section.