Approaches to the infrasound signal Approaches to the infrasound signal denoising by using denoising by using AR method AR method N. Arai, N. Arai, T. Murayama T. Murayama , and M. Iwakuni , and M. Iwakuni (Research Dept., Japan Weather Association) (Research Dept., Japan Weather Association) 2008 Infrasound Technology Workshop in Bermuda 2008 Infrasound Technology Workshop in Bermuda
13
Embed
Approaches to the infrasound signal denoising by using AR method N. Arai, T. Murayama, and M. Iwakuni (Research Dept., Japan Weather Association) 2008.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Approaches to the infrasound Approaches to the infrasound signal denoising by using signal denoising by using
AR methodAR method
N. Arai, N. Arai, T. MurayamaT. Murayama, and M. Iwakuni, and M. Iwakuni
(Research Dept., Japan Weather (Research Dept., Japan Weather Association) Association)
2008 Infrasound Technology Workshop in Bermuda2008 Infrasound Technology Workshop in Bermuda
Table of ContentsTable of Contents
MotivationMotivation Denoising by using Denoising by using statistical modelsstatistical models Example of estimation resultExample of estimation result Conclusion and future planConclusion and future plan
MotivationMotivation Wind and other background noise are Wind and other background noise are
included in the Observed Infrasound Dataincluded in the Observed Infrasound Data
Therefore,…Therefore,…• It is difficult to detect exactly arrival time of signalIt is difficult to detect exactly arrival time of signal• The signal of small amplitude may not be detected The signal of small amplitude may not be detected
And then,…And then,…• We want to see pure signal each event sourceWe want to see pure signal each event source
We need remove the background noise !!We need remove the background noise !!
Way to denoising of infrasound data ?Way to denoising of infrasound data ?
Noise Noise bandband
Signal Signal bandband
Signal Signal bandband
Noise Noise bandband
Limit of the frequency Limit of the frequency decomposition filterdecomposition filter
ff
Pow
er
Pow
er
sp
ectr
um
sp
ectr
um
ff
Pow
er
Pow
er
sp
ectr
um
sp
ectr
um
ff
Pow
er
Pow
er
sp
ectr
um
sp
ectr
um
???
< CASE 1 >< CASE 1 >
< CASE 2 >< CASE 2 >
filterinfilteringg
filterinfilteringg
ff
Pow
er
Pow
er
sp
ectr
um
sp
ectr
um
Observed Observed
Noise Noise
Signal Signal
Undetectable Undetectable levellevel
Detectable Detectable levellevel
Need other Need other Denoising metodDenoising metod
Image of the Denoising and the Extraction of Image of the Denoising and the Extraction of Infrasound SignalInfrasound Signal
Observed Infrasound Data Observed Infrasound Data WaveformWaveform
Conclusions and future Conclusions and future planplan
We have only begun to study the denoising of InfrWe have only begun to study the denoising of Infrasound monitoring data by using asound monitoring data by using statistical modstatistical models (AR model, State space model, Kalman filterels (AR model, State space model, Kalman filter…)…)
We really do not understand a effect of the denoiWe really do not understand a effect of the denoising by using statistical models at this timesing by using statistical models at this time
In order to clear a effect of the denoising, we will In order to clear a effect of the denoising, we will give in-depth consideration to give in-depth consideration to statistical models statistical models by using more events databy using more events data