Application of a Wavelet Extension De-Noising Method in Seismic Data Processing

2012 ◽  
Vol 622-623 ◽  
pp. 1670-1673
Author(s):  
Ye Wu ◽  
Bo Zhang ◽  
Jia Wei
Keyword(s):  
Fourier Transform ◽  
Seismic Data ◽  
High Frequency ◽  
The Other ◽  
Frequency Noise ◽  
Seismic Data Processing ◽  
High Frequency Noise ◽  
Filtering Method ◽  
Components Method ◽  
Coefficient Method

A new wavelet extension de-noising (WED) method is proposed in this paper. The basic principle is derived in detail. We have removed the high frequency noise in seismic data based on the suppressing detail components method, Fourier transform filtering method, WED method and reconstructing the 5th layer approximate coefficient method respectively, and the results show that the WED method can more effectively restrain noise than the other methods.

Multichannel absorption compensation with a data-driven structural regularization

Geophysics ◽  
2019 ◽  
Vol 85 (1) ◽  
pp. V71-V80 ◽  
Author(s):  
Xiong Ma ◽  
Guofa Li ◽  
Hao Li ◽  
Wuyang Yang
Keyword(s):  
Cost Function ◽  
Structural Characteristic ◽  
Seismic Data ◽  
High Frequency ◽  
Signal To Noise Ratio ◽  
Random Noise ◽  
Frequency Noise ◽  
Characteristic Operator ◽  
High Frequency Noise ◽  
The Cost

Seismic absorption compensation is an important processing approach to mitigate the attenuation effects caused by the intrinsic inelasticity of subsurface media and to enhance seismic resolution. However, conventional absorption compensation approaches ignore the spatial connection along seismic traces, which makes the compensation result vulnerable to high-frequency noise amplification, thus reducing the signal-to-noise ratio (S/N) of the result. To alleviate this issue, we have developed a structurally constrained multichannel absorption compensation (SC-MAC) algorithm. In the cost function of this algorithm, we exploit an [Formula: see text] norm to constrain the reflectivity series and an [Formula: see text] norm to regularize the reflection structural characteristic of the compensation data. The reflection structural characteristic operator, extracted from the observed stacked seismic data, is the core of the structural regularization term. We then solve the cost function of SC-MAC by the alternating direction method of multipliers. Benefiting from the introduction of reflection structure constraint, SC-MAC improves the stability of the compensation result and inhibits the amplification of high-frequency noise. Synthetic and field data examples demonstrate that our proposed method is more robust to random noise and can not only improve the resolution of seismic data, but also maintain the S/N of the compensation seismic data.

scholarly journals Enhanced Methods of Seasonal Adjustment

Econometrics ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 3
Author(s):  
D. Stephen G. Pollock
Keyword(s):  
Fourier Transform ◽  
Computer Program ◽  
High Frequency ◽  
Seasonal Adjustment ◽  
Frequency Noise ◽  
Conventional Model ◽  
High Frequency Noise ◽  
Model Based ◽  
At Will

The effect of the conventional model-based methods of seasonal adjustment is to nullify the elements of the data that reside at the seasonal frequencies and to attenuate the elements at the adjacent frequencies. It may be desirable to nullify some of the adjacent elements instead of merely attenuating them. For this purpose, two alternative sets of procedures are presented that have been implemented in a computer program named SEASCAPE. In the first set of procedures, a basic seasonal adjustment filter is augmented by additional filters that are targeted at the adjacent frequencies. In the second set of procedures, a Fourier transform of the data is exploited to allow the elements in the vicinities of the seasonal frequencies to be eliminated or attenuated at will. The question is raised of whether an estimated trend-cycle trajectory that is devoid of high-frequency noise can serve in place of the seasonally adjusted data.

scholarly journals Methods of Testing of Sound Insulation Properties of Barriers Intended for High Frequency Noise and Ultrasonic Noise Protection

2018 ◽  
Vol 68 (4) ◽  
pp. 55-64
Author(s):  
Pleban Dariusz ◽  
Mikulski Witold
Keyword(s):  
High Frequency ◽  
Test Chamber ◽  
Test Stand ◽  
The Other ◽  
Sound Insulation ◽  
Frequency Noise ◽  
Frequency Range ◽  
High Frequency Noise

AbstractTwo test stands for determining sound insulation in the frequency range above 5 kHz were made. One consisted of two horizontally adjacent reverberation rooms and a special source of high frequency sounds and ultrasounds. The other test stand consisted of a miniaturized test chamber and a special source of ultrasounds. The paper presents results of the preliminary measurements of sound insulation properties of different barriers in the frequency range above 5 kHz.

Study on MEMS Gyro Signal De-Noising Based on Improved Wavelet Threshold Method

2013 ◽  
Vol 433-435 ◽  
pp. 1558-1562 ◽  
Author(s):  
Yong Sheng Shi ◽  
Zhi Feng Gao
Keyword(s):  
High Frequency ◽  
Threshold Function ◽  
Frequency Noise ◽  
Defect Analysis ◽  
Threshold Method ◽  
Random Drift ◽  
Signal Filtering ◽  
High Frequency Noise ◽  
Filtering Method ◽  
Soft Threshold

An effective filtering method for MEMS gyro random drift is discussed. On the basis of the fundamentals and defect analysis of wavelet threshold de-noising, a new continuous threshold function at λ is presented, signal concussion and distortion in wavelet hard and soft threshold method is effectively overcome. The improved wavelet de-noising algorithm is applied to MEMS gyro signal filtering experiment and experimental results show that the proposed method can effectively reduce the high frequency noise, restrain the MEMS gyro random drift, increases the SNR and decrease the MSE.

scholarly journals Speech Separation in the Frequency Domain with Autoencoder

2020 ◽  
pp. 841-848
Author(s):  
Hao D. Do ◽  
◽  
Son T. Tran ◽  
Duc T. Chau
Keyword(s):  
Speech Signal ◽  
High Frequency ◽  
Bandpass Filter ◽  
The Other ◽  
Frequency Noise ◽  
Speech Separation ◽  
Related System ◽  
High Frequency Noise ◽  
Powerful Approach ◽  
And Performance

Speech separation plays an important role in a speech-related system because it can denoise, extract and enhance speech signal, and after all improve the accuracy and performance of the system. In recent years, many approaches only separate the speech out of commonly high-frequency noise or a particular background sound. We propose a more powerful approach, combining an autoencoder and a bandpass filter to separate speech signals. This combination can extract the speech in the mixture with not only high-frequency noise but also many kinds of different background sounds. Our approach can be flexibly applied for the new background sounds. Experimental results show that our model can extract fastly and effectively the speech signal with 9.01 dB in SIR and 11.26 in SDR. On the other hand, we can adjust the passband to identify the range of frequency at the output signal to apply for particular applications.

Case study: Simulation and control of high frequency noise for commercial vehicle cab considering leak

2019 ◽  
Vol 67 (4) ◽  
pp. 315-329
Author(s):  
Rongjiang Tang ◽  
Zhe Tong ◽  
Weiguang Zheng ◽  
Shenfang Li ◽  
Li Huang
Keyword(s):  
High Frequency ◽  
Commercial Vehicle ◽  
Frequency Noise ◽  
High Frequency Noise ◽  
Simulation And Control ◽  
And Control

Aerodynamic noise from an asymmetric airfoil with perforated extension plates at the trailing edge

2020 ◽  
pp. 1475472X2097838
Author(s):  
CK Sumesh ◽  
TJS Jothi
Keyword(s):  
High Frequency ◽  
Sound Pressure ◽  
Pore Diameter ◽  
Low Frequency ◽  
Aerodynamic Noise ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Trailing Edge ◽  
High Frequency Noise ◽  
Displacement Thickness

This paper investigates the noise emissions from NACA 6412 asymmetric airfoil with different perforated extension plates at the trailing edge. The length of the extension plate is 10 mm, and the pore diameters ( D) considered for the study are in the range of 0.689 to 1.665 mm. The experiments are carried out in the flow velocity ( U∞) range of 20 to 45 m/s, and geometric angles of attack ( αg) values of −10° to +10°. Perforated extensions have an overwhelming response in reducing the low frequency noise (<1.5 kHz), and a reduction of up to 6 dB is observed with an increase in the pore diameter. Contrastingly, the higher frequency noise (>4 kHz) is observed to increase with an increase in the pore diameter. The dominant reduction in the low frequency noise for perforated model airfoils is within the Strouhal number (based on the displacement thickness) of 0.11. The overall sound pressure levels of perforated model airfoils are observed to reduce by a maximum of 2 dB compared to the base airfoil. Finally, by varying the geometric angle of attack from −10° to +10°, the lower frequency noise is seen to increase, while the high frequency noise is observed to decrease.

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