Thread: FREQLIMITS

Started: 2014-10-02 21:49:53
Last activity: 2014-10-02 21:49:53
Topics: SAC Help
Hamidatul Husna Matondang
FREQLIMITS
2014-10-02 21:49:53
Dear Sir/Ms

How do I determine the freqlimits f1 f2 f3 f4? should I see the spectrum of the origin signal first or I can determine it randomly as long as f1 < f2
< f3 < f4? Thank You

Regards
Ami

  • Sheila Peacock
    Re: FREQLIMITS
    2014-10-02 15:40:13
    Dear Amik,

    I assume that the "freqlimits" are for the "transfer" command.
    Yes, do look at the spectrum. The choice of f1 and f4, in
    addition, needs regard for Gibbs' phenomenon. If f1 is
    too close to f2 (in logarithmic space) then you will
    get "ringing". I have a very crude rule of thumb to
    have f1 <= f2/2 and f4 > f3*2. There is of course no
    point in having f3 or f4 > Nyquist frequency.

    Sheila Peacock.

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