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+--- Thread: High resolution frequency detektor (/showthread.php?tid=656)
High resolution frequency detektor - Henrik_V - 02-17-2020
Hi,
great tool ..
I was trying to detect small frequency variations with my android and here is my feature request:
A high resolution frequency detector
Autocorrelation and FFT based solutions are limited by the samplerate and sample size, one would be the reciproque counting method.
But there are even better methods: sine fitting
EVALUATION OF A STANDARDIZED SINE WAVE FIT ALGORITHM
Peter Händel
Abstract:
The IEEE Standard 1057 provides algorithms for fitting the parameters of a sine wave to noisy discrete time observations....
Or doing some more math on a FFT like:
https://forums.ni.com/ni/attachments/ni/170/83640/1/tm3bb.ppt
found in
https://forums.ni.com/t5/LabVIEW/Extract-Single-Tone-Information-from-Hann-Spectrum/m-p/139348#M83640
works great in LabVIEW, but I don't know what is protected in that part....
Both method prefer sine like signals but also work on everything that is periodic
(one could apply a bandpass before)
My experiments are measure small frequency changes in a LC oscillator .. and detect small changes in µ_r or C ...
(and try to power the circuit from the mic bias .. ;
) Regards
Henrik
RE: High resolution frequency detektor - Sebastian Staacks - 02-20-2020
Thanks for the suggestion. I intended to implement some other methods for a while now, but never got around to it. I will bump it up a little bit on my todo list, but not yet sure when I will get to it. (This is something that could easily be contributed to our open source project as a new analysis module by someone who can write Java and/or Swift, just saying
)