In message <[EMAIL PROTECTED]>, "Ulrich Bangert" writes: >Hello Paul-Henning, > >www.tmo.jpl.nasa.gov/progress_report/42-121/121G.pdf > >definitely uses no FFT but uses a theoreme from geometry to estimate the >signal's frequency and the rest is a two dimensional non-linear fit for >amplitude and phase. But i am starting to understand how a FFT might be >helpfull too. > >Does it involve finding the maximum of the frequency spectrum by >interpolating between frequency bins and then find the matching >(interpolated) phase bin?
That would depend on your sampling rate. If you sample a 1Hz signal 96k times a second, interpolation between bins would probably just be a waste of time. Alternatively, you could apply a really steep band-pass filter around 1 Hz. Something like an 1131 pole FIR filter, and then find the zero crossing geometrically using the three points around the zero line. -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
