Is 0.001Hz resolution possible with a 2.5Ms/s file while preserving the time resolution?
3 views (last 30 days)
Show older comments
I have an audio signal that was sampled at 2.5Ms/s, 24bit resolution, 10min. in duration, captured to a wave file. The signal bandwidth is 1MHz.
Is it possible to setup the fft function with a large enough fft size (bins) to have 0.001Hz resolution while preserving the time resolution? I suspect that this may require a fft size of 500M or larger to acheive. The output will be a spectragraph plot(s).
Is this possible with the Signal Processing Toolbox?
Computing power and speed is not an issue.
Thanks, Jonathan
0 Comments
Accepted Answer
Wayne King
on 29 Jun 2012
Edited: Wayne King
on 29 Jun 2012
It sounds like you have
dt = 1/2.5e6;
N = 600/dt;
N samples is that correct? To achieve a frequency resolution of 0.001 Hz with a sampling rate of 2.5 megahertz you need
1/(0.001*dt)
samples, which you don't have. Padding the fft does not increase your frequency resolution. That is determined by your sampling rate and the number of samples you acquire. Padding the fft() only interpolates the frequency grid.
So in short, no, you don't have enough data for the DFT to have 0.001 Hz resolution, let alone the short-time Fourier transform for which you would have to segment your data.
0 Comments
More Answers (0)
See Also
Categories
Find more on Fourier Analysis and Filtering in Help Center and File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!