Multiple 6C-station Huddle Test in Fürstenfeldbruck, Germany

Rotational motions play a key role in measuring seismic wavefield properties. To fully understand and describe the behavior of seismic waves, both translational and rotational components should be properly investigated. Portable blueSeis-3A (iXblue) sensors allow to measure 3 components of rotational motions with high sensitivity in a frequency range from 0.001 Hz to 50 Hz.A huddle test was performed in F&#252;rstenfeldbruck, Germany by the University of Potsdam in collaboration with the Ludwig-Maximilians University of Munich (LMU) and Federal Institute for Geosciences and Natural Resources (BGR) between 26 of August and 02 of September 2019, in order to further investigate the performance of multiple rotational instruments in combination with seismometers. Within the scope of this test, 5 rotational and 3 translational sensors were deployed on the basement of the observatory on decoupled plinth. Our preliminary results show good correlation between all components and rotational sensors. To investigate the coherent noise between sensors, we applied a 50 Hz low-pass filter and 100 Hz sampling rate. To better illustrate, probabilistic power spectral densities and spectrograms have been created. In general, we will discuss the reliability of the data recorded by rotational sensors for further investigations.&#160;

Download Full-text

A sampling rate increasing method using matrix low-pass filter and discrete cosine transform

2016 IEEE International Conference on Consumer Electronics-Taiwan (ICCE-TW) ◽

10.1109/icce-tw.2016.7520916 ◽

2016 ◽

Author(s):

Chien-Cheng Tseng ◽

Su-Ling Lee

Keyword(s):

Discrete Cosine Transform ◽

Sampling Rate ◽

Pass Filter ◽

Low Pass Filter ◽

Cosine Transform ◽

Low Pass

Download Full-text

Data Acquisition System Connect to CMG-3T Low-Frequency Seismic Pendulum

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.734-737.2945 ◽

2013 ◽

Vol 734-737 ◽

pp. 2945-2948

Author(s):

Ting Ting Liu ◽

Yong Wu ◽

Jun Lin

Keyword(s):

Data Acquisition ◽

Seismic Waves ◽

Low Frequency ◽

Data Acquisition System ◽

Low Noise ◽

Acquisition System ◽

Power Module ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass

Aiming at the low-frequency performance of the lowfrequency seismic pendulum CMG -3T, we design a data acquisition system can acquire the low-frequency seismic waves, at the same time we accomplish the process of adjusting the CMG-3T. This paper gives designing scheme include the low noise design of the power module, the design of the connector to RS232 which can send command to adjusting the mass of CMG-3T,the design of voltage attenuation network and no-source low-pass filter network of data acquisition system, the last is the design of software for adjusting the CMG-3T.

Download Full-text

Design and Research of Digital Decimation Filter Based on FPGA

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.2086 ◽

2011 ◽

Vol 105-107 ◽

pp. 2086-2091

Author(s):

Yao Li

Keyword(s):

High Speed ◽

Sampling Rate ◽

Comb Filter ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

Cic Filter ◽

Decimation Filter ◽

Fpga Chip ◽

Digital Down Conversion

This paper studies and analyses various digital filter and decimation structure. On this basis, by using QUARTUS development system design the decimation device modules, through the waveform simulation validated its correctness. Finally,a program is written into FPGA chip by the hardware platform. In the digital down conversion (DDC), CIC (cascade integral comb) filter plays an important role. It is mainly used for sampling rate, as well as low-pass filter effect. The main characteristics of CIC filter, using only adders, subtractor and register (no multiplier), so fewer resources occupied, implementation is simple and high speed. Based on the analysis of the principle of CIC filter,simulate and synthesize based on the theory of using VHDL language in FPGA. And successful application in the development of DDC chip. Keyword: CIC (cascade integral comb) filter,FPGA,VHDL

Download Full-text

Computing efficiency of the three-stage interpolated low pass filters

Radio Industry (Russia) ◽

10.21778/2413-9599-2018-28-4-21-27 ◽

2018 ◽

Vol 28 (4) ◽

pp. 21-27

Author(s):

I. S. Savinykh ◽

D. A. Chemasov

Keyword(s):

Impulse Response ◽

Computational Efficiency ◽

Finite Impulse Response ◽

Sampling Rate ◽

Efficiency Coefficient ◽

Transition Band ◽

Pass Filter ◽

Low Pass Filter ◽

Low Pass ◽

Low Pass Filters

Undoubted advantages of finite impulse response filters are their unconditional stability, the absence of limit cycles and the possibility of implementing a filter that does not introduce phase distortion. The disadvantage of such filters is the large cost required to compute the response. This paper considers three-stage interpolated finite impulse response low-pass filters. The maximum values of the interpolation factors are determined. Dependences of the coefficient of computational efficiency and the coefficient of increase in the registers of the three-stage interpolated low-pass filter on the values of the interpolation factors, the widths of the passband and the transition band are obtained. Relations for determining the optimal values of interpolation factors corresponding to the maximal value of computational efficiency coefficient are obtained. In addition, the dependencies of the maximum coefficient of computational efficiency and the optimal coefficient of increase in the registers of the three-stage interpolated low-pass filter on the widths of the passband and the transition band at the optimum values of the interpolation factors are obtained. Considered three-stage interpolated low-pass filters should be used in the case when the required stopband is significantly less than the sampling rate. In this case, three- stage interpolated filters require less computational resources for calculating the response than the two-stage interpolated filters or filter implemented by the transversal structure.

Download Full-text

Influence of noise and sampling rate on the discrete image representation error

Information and Control Systems ◽

10.31799/1684-8853-2021-5-33-39 ◽

2021 ◽

pp. 33-39

Author(s):

Alexander Timofeev ◽

Albert Sultanov

Keyword(s):

Noise Level ◽

Sampling Error ◽

Sampling Rate ◽

Sampling Frequency ◽

Noise Component ◽

Pass Filter ◽

Low Pass Filter ◽

Image Sampling ◽

Representation Error ◽

Low Pass

Introduction: Digital registration of images is accompanied not only by an error caused by finite spatial resolution of the photo matrix, but also by the effect of noise whose contribution to the total error decreases with an increase in the aperture of the photosensors in the matrix. Thus, changing the sampling rate has the opposite effect on the sampling error and on the error caused by the noise. Purpose: Finding the optimal image sampling rate which would provide the minimum sampling error in the presence of noise. Results: We have studied how an image discrete representation error depends on the sampling frequency and noise level. The image sampling process in the presence of noise was simulated in the MATLAB environment. The dependencies of the root-mean-square deviation of the sampling error caused by spectrum truncation (decrease in the passband of the low-pass filter) and the noise component of the error on the sampling frequency were plotted. A theorem is formulated on the upper bound of the sampling theorem: when sampling a function of finite duration in the presence of noise, there is a finite minimum value of the sampling error which is determined by the shape of the spectrum of the function and the noise level. Practical relevance: It is advisable to use the research results when choosing a photomatrix by the number of pixels for recording images in the presence of noise, as well as when choosing a low-pass filter passband for primary processing of a digital image.

Download Full-text