[fpc-pascal] Good FFT example anywhere?

Bo Berglund bo.berglund at gmail.com
Mon Apr 10 23:20:21 CEST 2017

On Mon, 10 Apr 2017 09:58 +0200, Michael Schnell
<mschnell at lumino.de> wrote:

>>It will produce 8192 samples
>>for each measurement.
> If the "measurements" come as a sequence of sample-blocks, you 
> additional to the core FFT will need a sliding Window algorithm to e.g. 
> create something like a life spectrum display or do a useful convolution.

Well, it is actually like this:
- A pulse stimulus is applied to the object to measure
- The response transient is recorded for up to 150 ms

The task now is to analyze the single transient for its constituent
frequencies (amplitude and phase) because these hold information about
the measured object.

The used 24 bit A/D converter can sample up to 50 KSMPS, but we don't
know if this is really necessary. In any case 164 ms of 50 kHz
sampling gives us 8192 samples to work with, reduce the rate to half
and we have 4096 samples for the same time instead.

Bo Berglund
Developer in Sweden

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