Return to command index

direction of polarisation

command: MDIR <trc-list> <wdw-lo> <wdw-hi> [<azim>] [<inci>]

Determines the direction of maximum polarisation in two or three dimensions. The direction is determined by diagonalising the coherence matrix of the specified traces in the given time window. The direction of the eigenvector with the largest eigenvalue is the desired direction. The output angles can be used directly as input values for a rotation (ROT command) to get an optimum separation of components. The MDIR command operates in 2-dim or 3-dim mode depending on the length of <trc-list> (2 or 3 traces).

parameters

• <trc-list> parameter type: trace list
  List of 2 or 3 traces to determine direction of polarisation.

• <wdw-lo>, <wdw-hi> parameter type: real
  Time window for computation of direction of polarisation.

• <azim> parameter type: symbol address
  Symbol to receive the value of azimuth (2- or 3-dimensional mode).

• <inci> parameter type: symbol address
  Symbol to receive value of angle of incidence. Valid only in 3-dimensional mode.

examples

mdir 1,2 100.0 110.0

computes rotation angle in time window from 100.0 to 110.0 sec the result is displayed.

mdir 1,2 100.0 110.0 &AZIM

computes rotation angle in time window from 100.0 to 110.0 sec the result is stored in symbol "AZIM"

mdir 1-3 10.0 20.0 &A &I

computes two rotation angles in time window from 10.0 to 20.0. The results are stored in "A" and "I".