High resolution frequency detektor - Printable Version +- phyphox Forums (https://phyphox.org/forums) +-- Forum: App-Feedback (https://phyphox.org/forums/forumdisplay.php?fid=6) +--- Forum: Feature requests (https://phyphox.org/forums/forumdisplay.php?fid=8) +--- 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 )