13.9 FFT Analysis Modes
248
Waveform Example
Auto Correlation Function
Shows the correlation of two points on the input signal at time differential
t
.
Main uses:
• To detect periodicy in irregular signals (improving and detecting SNR)
• To inspect periodic components in a noisy waveform.
See:
About the Functions
"13.9.2 Analysis Mode Functions" (
Axis
Display Type
Description
X axis
Linear
Time display
The center (
t
= 0) is the reference. To the right is lag time (+
t
), and to the left is
lead time (-
t
)
Y axis
Lin-Mag
+1 to -1 (dimensionless units)
The closest correlation at time differential
t
is +1, and the least correlation is 0.
-1 indicates completely reversed polarity.
Because of the characteristics of the function,
t
= 0 b1.
X axis: Linear
Y axis: Lin-Mag
This instrument provides a circular auto-correlation function. Analysis results are
normalized to the maximum value.
Summary of Contents for 8847
Page 1: ...MEMORY HiCORDER Instruction Manual 8847 December 2010 Revised edition 4 8847A981 04 10 12H ...
Page 2: ......
Page 18: ...Operating Precautions 8 ...
Page 26: ...1 4 Basic Key Operations 16 ...
Page 74: ...4 4 Waveform Observation 64 ...
Page 98: ...5 5 Managing Files 88 ...
Page 110: ...6 6 Miscellaneous Printing Functions 100 ...
Page 126: ...7 8 Seeing Block Waveforms 116 ...
Page 160: ...8 10 Making Detailed Settings for Input Modules 150 ...
Page 198: ...10 6 Numerical Calculation Type and Description 188 ...
Page 296: ...15 7 Controlling the Instrument with Command Communications LAN USB 286 ...
Page 304: ...16 2 External I O 294 ...
Page 362: ...Appendix 5 FFT Definitions A28 ...
Page 368: ...Index Index 6 ...
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