Analysis of windowing/leakage effects in frequency response function measurements
| Authors: | Schoukens Johan, VUB, Belgium
Rolain Y., VUB, Belgium
Pintelon R., VUB, Belgium |
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| Topic: | 1.1 Modelling, Identification & Signal Processing |
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| Session: | Frequency Domain Estimation Methods |
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| Keywords: | system identification, frequency response function measurement, leakage, windowing |
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Abstract
This paper analyses the errors on the frequency response function measurement of a transfer function due to finite window effects (leakage). First an analysis of the rectangular and the Hanning window is made. It will be shown that the leakage error consists of two components: a transient error due to initial and end conditions effects, and an interpolation error due to the combination of neighbouring spectral lines. Eventually, a new ‘default’ window is proposed with slightly better properties. This allows to reduce the measurement time with 25% if the leakage errors dominate the disturbing output noise.
