[time-nuts] Calculate spectral content from a series of zero crossing time stamps?

Henk henk at deriesp.demon.nl
Tue Feb 8 21:19:38 UTC 2011


Hi,

Wavecrest uses algorithms for this and their software gives a spectrum. They also give some info on their site.

Henk


Op 8 feb 2011, om 20:51 heeft Detlef.Amberg at gmx.de het volgende geschreven:

> 08.02.2011 08:17, Poul-Henning Kamp:
>> In message <224676.41616.qm at web120905.mail.ne1.yahoo.com>, Tijd Dingen writes:
>> 
>>>> From what I could find so far, one method to go about this is use a
>>> Lomb/Scargle Periodogram. And specifically the method by Press & Rybicki that
>>> extirpolates the unevenly timed samples to an regular timed mesh, after which
>>> a regular DFT is done.
>> 
>> Just knowing the time of the zero-crossings is very little information
>> to go by, but you have to make some kind of assumption about the
>> perfection of curve shape between those points, in order to say
>> anything meaningful.
> 
> As far as I know a bandpass signal is described uniquely by its zero
> crossings to within a constant. That is due to the Weierstrass
> factorization theorem. A more practical foundation is outlined in
> "B.F.Logan: 'Information in the zero crossings of bandpass signals', The
> Bell System Technical Journal vol. 56 Number 4, April 1977" and some
> other publications by the same author in the same journal.
> 
> Recently these techniques have been exploited in 'zepoc' algorithms for
> low power hifi class D amplifiers and the 'click modulation' scheme.
> 
> But there were also publications which were in doubt that a real valued
> signal can be reconstructed by its zero crossings.
> 
> Sadly, my mathematical background is not sufficient to follow the
> arguments. But nonetheless zero crossing algorithms and nonuniform
> sampling are very promising fields.
> 
> Cheers
> Detlef
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.





More information about the Time-nuts_lists.febo.com mailing list