The spectral analysis of magnetotelluric (MT) data for impedance tensor estimation requires the stationarity of measured magnetic (H) and electric (E) fields. However, it is well known that noise biases time-domain tensor estimates obtained via an iterative search by a descent algorithm to determine the least-mean-square residual between measured and estimated E data obtained from H data. To limit the noise that slows down, or even prevents convergence, the steepest descent step size is based upon the statistics of the residual. The time-domain technique is applied to data sets from the EMSLAB Juan de Fuca project as well as to data from a southern Italian site. -from Author
Time domain estimation of MT impedance tensor
Spagnolini, U.
1994-01-01
Abstract
The spectral analysis of magnetotelluric (MT) data for impedance tensor estimation requires the stationarity of measured magnetic (H) and electric (E) fields. However, it is well known that noise biases time-domain tensor estimates obtained via an iterative search by a descent algorithm to determine the least-mean-square residual between measured and estimated E data obtained from H data. To limit the noise that slows down, or even prevents convergence, the steepest descent step size is based upon the statistics of the residual. The time-domain technique is applied to data sets from the EMSLAB Juan de Fuca project as well as to data from a southern Italian site. -from AuthorI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.