Detection of Seismic Wave with Laser Interferometer

In this paper, we propose a seismic wave detection process using a laser interferometer as a seismometer. The laser interferometer system is an important equipment with its remarkable accurate capability for displacement measurement. During the process of the seismic wave measurement, however, environmental and nonlinearity error are occurred in a heterodyne laser interferometer. Through the extended Kalman filter compensation, the distortion is reduced. With a recursive STA/LTA algorithm, the PS-time of the seismic wave is determined and then the epicenter distance can be derived. Through some simulations, it is demonstrated that the proposed algorithm can reduce error factors and improve the measurement accuracy of a seismometer.

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Improved Measurement Accuracy of a Laser Interferometer: Extended Kalman Filter Approach

IEICE Transactions on Fundamentals of Electronics Communications and Computer Sciences ◽

10.1587/transfun.e93.a.1820 ◽

2010 ◽

Vol E93-A (10) ◽

pp. 1820-1823 ◽

Cited By ~ 1

Author(s):

Wooram LEE ◽

Dongkyun KIM ◽

Kwanho YOU

Keyword(s):

Kalman Filter ◽

Extended Kalman Filter ◽

Measurement Accuracy ◽

Laser Interferometer ◽

Filter Approach

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Vibration Error Correction for the FOGs-Based Measurement in a Drilling System Using an Extended Kalman Filter

Applied Sciences ◽

10.3390/app11146514 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6514

Author(s):

Lu Wang ◽

Yuanbiao Hu ◽

Tao Wang ◽

Baolin Liu

Keyword(s):

Kalman Filter ◽

Extended Kalman Filter ◽

Measurement Accuracy ◽

Original Data ◽

Calibration Method ◽

Error Model ◽

Nonlinear Error ◽

Measurement While Drilling ◽

Drilling System ◽

Vibration Error

Fiber-optic gyroscopes (FOGs)-based Measurement While Drilling system (MWD) is a newly developed instrument to survey the borehole trajectory continuously and in real time. However, because of the strong vibration while drilling, the measurement accuracy of FOG-based MWD deteriorates. It is urgent to improve the measurement accuracy while drilling. Therefore, this paper proposes an innovative scheme for the vibration error of the FOG-based MWD. Firstly, the nonlinear error models for the FOGs and ACCs are established. Secondly, a 36-order Extended Kalman Filter (EKF) combined with a calibration method based on 24-position is designed to identify the coefficients in the error model. Moreover, in order to obtain a higher accurate error model, an iterative calibration method has been suggested to suppress calibration residuals. Finally, vibration experiments simulating the drilling vibration in the laboratory is implemented. Compared to the original data, compensated the linear error items, the error of 3D borehole trajectory can only be reduced by a ratio from 10% to 34%. While compensating for the nonlinear error items of the FOG-based MWD, the error of 3D borehole trajectory can be reduced by a ratio from 44.13% to 97.22%. In conclusion, compensation of the nonlinear error of FOG-based MWD could improve the trajectory survey accuracy under vibration.

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Key technologies analysis and design of ultra-clean & ultra-stable spacecraft for gravitational wave detection

International Journal of Modern Physics A ◽

10.1142/s0217751x21400212 ◽

2021 ◽

pp. 2140021

Author(s):

Kun Chen ◽

Xiaofeng Zhang ◽

Tong Guo ◽

Zhi-Ming Cai ◽

Keyword(s):

Gravitational Wave ◽

Measurement Accuracy ◽

Laser Interferometer ◽

Gravitational Interaction ◽

Thermal Control ◽

Theory Of Relativity ◽

Gravitational Wave Detection ◽

Analysis And Design ◽

Wave Detection ◽

Key Technologies

The observation of gravitational wave enables human to explore the origin, formation and evolution of universe governed by the gravitational interaction and the nature of gravity beyond general theory of relativity. The groundbreaking discovery of Gravitational Wave by Laser Interferometer Gravitational-Wave Observatory provides a brand-new observation way. While detecting gravitational wave on ground is limited by noises and test scale, space detection is an optimized alternative to learn rich sources in range of 0.1 mHz–1 Hz. Considering the great significance of space gravitational wave detection, ESA proposed LISA project, CAS also proposed Taiji project. Due to the extremely weak gravitational wave signal and high measurement accuracy requirement, the spaceborne GW observation antenna is accomplished by three spacecrafts constitute isosceles triangle formation intersatellite interferometer. The arm length of the interferometer reaches millions of kilometers between them, and the measurement accuracy reaches pico-meter magnitude. There are many key technologies including pm magnitude space laser interferometer metrology, drag-free control using TM of Gravity Reference Sensor, [Formula: see text]N micro thruster, ultra-clean & ultra-stable spacecraft, etc. This paper focuses on key technologies of the ultra-clean & ultra-stable spacecraft, analyzing the design of mechanical, thermal control and magnetic clean. Moreover, it reports the preliminary results of the technological breakthrough.

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A Phase Difference Measurement Method Based on the Extended Kalman Filter for Coriolis Mass Flowmeters

Measurement Science Review ◽

10.2478/msr-2019-0008 ◽

2019 ◽

Vol 19 (2) ◽

pp. 48-52

Author(s):

Nan Chen ◽

Shangchun Fan ◽

Dezhi Zheng

Keyword(s):

Kalman Filter ◽

Extended Kalman Filter ◽

Phase Difference ◽

Measurement Method ◽

Measurement Accuracy ◽

Single Phase ◽

Signal Frequency ◽

Difference Measurement ◽

Mallat Algorithm ◽

Interference Signals

Abstract According to the characteristics of stable single-phase flow, a phase difference measurement method based on the extended Kalman filter is proposed in this paper for use with Coriolis mass flowmeters. Firstly, the Mallat algorithm is applied to filter out interference signals. Then, the frequency and phase difference of the two reconstructed signals are detected through the extended Kalman filter. Compared with the sliding Goertzel algorithm or discrete time Fourier transform, the proposed method does not need to predict the signal frequency and avoids quadratic error. Simulations and experiments show that the proposed method has stronger anti-interference, higher measurement accuracy and lower relative error than the existing method based on the Hilbert transformation.

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Seismic Discrimination between Earthquakes and Explosions Using Support Vector Machine

Sensors ◽

10.3390/s20071879 ◽

2020 ◽

Vol 20 (7) ◽

pp. 1879

Author(s):

Sangkyeum Kim ◽

Kyunghyun Lee ◽

Kwanho You

Keyword(s):

Support Vector Machine ◽

Hough Transform ◽

Laser Interferometer ◽

Kernel Functions ◽

P Wave ◽

Support Vector ◽

Nonlinearity Error ◽

Seismic Discrimination ◽

Heterodyne Laser Interferometer ◽

Discrimination Method

The discrimination between earthquakes and explosions is a serious issue in seismic signal analysis. This paper proposes a seismic discrimination method using support vector machine (SVM), wherein the amplitudes of the P-wave and the S-wave of the seismic signals are selected as feature vectors. Furthermore, to improve the seismic discrimination performance using a heterodyne laser interferometer for seismic wave detection, the Hough transform is applied as a compensation method for the periodic nonlinearity error caused by the frequency-mixing in the laser interferometric seismometer. In the testing procedure, different kernel functions of SVM are used to discriminate between earthquakes and explosions. The outstanding performance of a laser interferometer and Hough transform method for precision seismic measurement and nonlinearity error compensation is confirmed through some experiments using a linear vibration stage. In addition, the effectiveness of the proposed discrimination method using a heterodyne laser interferometer is verified through a receiver operating characteristic curve and other performance indices obtained from practical experiments.

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