Prev: Filtering with Power of 2 Coefficients
Next: Phase between multiple channels with phase vocoder pitch shifting
From: jim on 15 Apr 2010 07:34


CCoder wrote:

> I am trying to measure coating thickness (100µ to 500µ) on a metal object
> (.5-20mm thick).

Is the idea to develop a non-destructive quality control test for paint
(or whatever the coating material is)? Have you looked at signals from
different samples with known coating thickness?

-jim



>
> >For identifying the presence and location
> >of discontinuities, a matched filter is probably a better choice.
>
> Which one? Amplitude level doesn't seem to give me any indication, maybe
> the frequency does, but I still have to check that part.
>
> >Either one will have to take the presence of noise into account; correct
> >deconvolution in a no-noise environment would be a horrible noise
> >enhancer, in the matched filter case the filter itself wouldn't change
> >much, but setting the threshold properly would get more and more dicey
> >as the noise went up.
>
> As far as I understand it now, noise is the factor which makes it difficult
> to find the correct thickness. In other words, the problem is to find the
> *correct* peak.
First  |  Prev  | 
Pages: 1 2 3 4
Prev: Filtering with Power of 2 Coefficients
Next: Phase between multiple channels with phase vocoder pitch shifting