Another interesting generalization of the DFT is the Lomb-Scargle transformation, which doesn't require a fixed measurement interval in the time domain. It is

Another interesting generalization of the DFT is the Lomb-Scargle transformation, which doesn't require a fixed measurement interval in the time domain. It is often used to determine the frequency of a period signal when you don't have fixed measurement interval, like in astrophysics. https://iopscience.iop.org/article/10.3847/1538-4365/aab766 https://iopscience.iop.org/article/10.3847/1538-4365/aab766 has a general introduction, and https://docs.astropy.org/en/stable/timeseries/lombscargle.html https://docs.astropy.org/en/stable/timeseries/lombscargle.ht... is a nice intro to using it in the astropy library (in Python)