Adapting multitaper spectrograms to local frequency modulation

This paper presents further extensions to the multitaper time-frequency spectrum estimation method developed by the author. The method uses time-frequency (TF) concentrated basis functions which diagonalize the nonstationary spectrum generating operator over a finite region of the TF plane. Individual spectrograms computed with these eigenfunctions form direct TF spectrum estimates, and are combined to form the multitaper TF spectrum estimate. A method is presented for adapting the multitaper spectrogram to locally match frequency modulation in the signal, which can cause broadening of the spectral estimate. An F-test for detecting and removing frequency-modulated tones is also given