Smoothing Windows

[Luanna]

Hello!
I´m developing a frequency analysis tool and  i´d like that my power density spectrum peaks were as close as possible to Gaussian curves. Does anybody know the best smoothing window  i could use to get that?

Thank you,

Luanna

[Tania_Lozoya]

Hi Luanna,

The smoothing windows are use to prevent Spectral Leakage (http://zone.ni.com/devzone/conceptd.nsf/webmain/81E934672ABEB3D4862568C1006528F4)

There are many windows you can use to do this, and there is no absolute better window, it depends on the application, as far as I know, here is a list of the windows you can find in LabVIEW:

http://zone.ni.com/reference/en-XX/help/371361B-01/lvanls/window_vis/

There is a Gaussian window:

http://zone.ni.com/reference/en-XX/help/371361B-01/lvanls/gaussian_window/

Hope this is helpful, let me know how it goes, it sound very interesting!

Tania Lozoya

[Kevin_Price]

Also, fundamentally, the best reproduction of a "gaussian-shaped curve" in frequency domain is only possible with very fine frequency resolution, so you need lots of individual points defining a peak.  Fine freq resolution in turn depends on rather long sampling durations.

In the real world, pure gaussians are pretty rare little beasties though anyway.  Quite often very fine frequency resolution just provides more "landing zones" for the broadband noise, and you still don't get nice well-defined gaussian curves.  FYI.

-Kevin P.