High-resolution frequency method to recover natural resonances of a conducting target from its transient response

A new method is proposed to extract the natural resonances contained in the time-domain response of a conducting target when it is illuminated by a plane electromagnetic wave of finite duration. This scheme is based on the introduction of a new covariance-type matrix of third-order data correlations on which the matrix pencil (MP) method is applied. Simulation results, even when data are contamined by coloured noise, show that this new method is especially useful, in comparison with the classical biased-type estimator, when the amount of data is small and the target natural-resonances have similar frequencies