160
────────────────────────────────────────────────────
8.7 FFT Analysis Function
────────────────────────────────────────────────────
8.7.11 Coherence [COH]
Function
Gab*
Gab
COH = ─────
Gaa･Gbb
Horizontal
cursor
Vertical
cursor
NOTE
Stored waveform (input signal) Stored waveform (output signal)
Coherence
Displays the output signal component that is coherent (interference possible)
to the input signal, yielding a value from 0 to 1.
Major applications include:
・Evaluation of transfer functions.
・Determining the contribution of individual input lines to the output of
multi-input systems.
LIN-Hz Frequency spectrum display as linear units. The range is from
DC to the maximum frequency range value.
LOG-Hz Frequency spectrum display as logarithmic units. The range is
from between 1/400 and 1/4000 of value to the frequency
range value.
Linear The relationship between the two input signals. The degree of
relationship is indicated from 0 to 1 on a linear scale (no
units).
For a single measurement, the coherence function returns 1 for all
frequencies. When measuring, be sure to use frequency averaging.
Example Coherence function waveforms
To Next Page
Loading...
