Fast and accurate transmission lines estimator

A new estimator for the identification of transmission lines based on the skin-effect equivalent circuit consisting of resistors and inductors is proposed and is named Log²ELiS (Logarithmic-Squared-ELiS). A software package that calculates the parametric maximum likelihood estimate of transfer functions, i.e. ELiS (Estimation of Linear Systems); already exists. ELiS allows accurate modelling of lumped linear systems from noisy observations and permits the estimation of the delay and the system parameters. Due to the delay, the cost function using ELiS has a lot of local minima and one needs good parameter starting values to obtain the global minimum. Both ELiS and Log²ELiS were applied to a practical measurement problem such as the identification of a transfer function with time delay. The simulation as well as measurement results have proven that Log² ELiS is better estimator to characterise transmission lines