Comment on "The T-class of time-frequency distributions : time-only kernels with amplitude estimation"

It is shown that the recently introduced T-class of time–frequency distributions is a subclass of the S-method distributions. From the generalization of the S-method distribution by rotating it in the time–frequency plane, a similar generalization of the T-class distribution follows readily. The generalized T-class distribution is then applicable to signals that behave chirp like, with their instantaneous frequency slowly varying around the slope of the chirp; this slope needs no longer be zero, as is the case for the original T-class distribution, but may take an arbitrary value.