GENERAL SMOOTHING TECHNIQUES FOR ESTIMATING DETERMINISTIC UNDAMPED SINUSOIDAL FREQUENCIES FROM NOISY DATA

General high-resolution smoothing techniques for estimating determinis tic sinusoidal frequencies from short-record noisy data, are presented . Symmetric smoothings are proven to provide conjugate reciprocals pol ynomial roots also in the noisy case and thereby eliminate spurious fr equency estimates. In numerical simulations they provided the lowest t hreshold of any currently existing method.