[time-nuts] simple phase finder

[Gregory Maxwell]

On Wed, Dec 5, 2018 at 11:12 PM Detlef.Amberg at gmx.de
<Detlef.Amberg at gmx.de> wrote:
> if you need the frequency, amplitude and phase of a sampled sine wave
> there is a solution without correlation, nonlinear fit or interpolation
> in the frequency domain. It works with damped sine waves as well.
>
> You just have to solve a linear system of equations.

A similar linerization can be used in an iterative manner to also
solve for first and higher order amplitude modulation as well as
frequency modulation:

https://people.xiph.org/~xiphmont/demo/ghost/demo3.xhtml

Also relevant is
https://github.com/stevengj/harminv/blob/master/README.md though
generally less flexible than the ghost chirp code.

What I've never known is how to characterize the statistics of these
kinds of matchers.