Study of High Precision Frequency Measurement Method of Power System Based on DSP

2011 ◽  
Vol 403-408 ◽  
pp. 3030-3034
Author(s):  
Cui Yun Gao ◽  
Ming Liu ◽  
Wen Jing Li ◽  
Ru Han
Keyword(s):  
Power Systems ◽  
High Precision ◽  
High Frequency ◽  
Detection Method ◽  
Signal To Noise Ratio ◽  
Frequency Measurement ◽  
Frequency Noise ◽  
Zero Crossing ◽  
Signal Simulation ◽  
Precision Frequency

In the power systems, frequency is an important parameter for harmonic analysis. This paper proposes a modified high precision zero-crossing detection method. The high frequency noise will affect the power system’s frequency measurement, FIR processing is used for the power signal. Simulation shows that after effective De-noising or when the signal-to-noise ratio (SNR) is higher, the method can reach the precision of 0.01Hz and meet the requirements of frequency measurement precision.

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.

Ultra-high Precision Frequency Measurement Research

2016 ◽  
Vol 9 (6) ◽  
pp. 341-348
Author(s):  
Wang Xuanmin ◽  
Huang Lijun ◽  
Qu Bayi
Keyword(s):  
High Precision ◽  
Frequency Measurement ◽  
Precision Frequency

Application with Wavelet Detection to Signal Process of SINS

2012 ◽  
Vol 571 ◽  
pp. 671-675
Author(s):  
Xiang Yuan Huang ◽  
Xia Qing Tang ◽  
Li Bi Guo ◽  
Xu Wei Cheng
Keyword(s):  
High Frequency ◽  
Simulation Experiment ◽  
Detection Method ◽  
Low Frequency ◽  
Frequency Noise ◽  
Wavelet Filter ◽  
Initial Alignment ◽  
Signal Process ◽  
Signal Characteristic ◽  
Alignment Process

Aimed at disturbance caused from motor running and personnel ambulation during initial alignment process of SINS, a new signal detection method of disturbance based on wavelet analysis is brought out. Through analyzing original signal characteristic of FOG and the data with wavelet filter on disturbance base, finds out wavelet filter just have effectiveness to high frequency noise. Then T&L signal detecting law is introduced, and builds T&L signal with high frequency part of wavelet decomposing to estimates interfere time and then resample. Offline simulation experiment results indicate the method can eliminate low frequency disturbance effectively and has certain apply value.

High-precision frequency measurement system based on different frequency quantization phase comparison

Measurement ◽  
2018 ◽  
Vol 122 ◽  
pp. 220-223 ◽  
Author(s):  
Baoqiang Du ◽  
Songlin Li ◽  
Guangming Huang ◽  
Xin Geng ◽  
Zhuo Li ◽  
...  
Keyword(s):  
High Precision ◽  
Measurement System ◽  
Frequency Measurement ◽  
Precision Frequency

Comparison of F o Extraction Methods for High-Precision Voice Perturbation Measurements

1993 ◽  
Vol 36 (6) ◽  
pp. 1120-1133 ◽  
Author(s):  
Ingo R. Titze ◽  
Haixiang Liang
Keyword(s):  
High Precision ◽  
Amplitude Modulation ◽  
Extraction Method ◽  
Signal To Noise Ratio ◽  
Extraction Methods ◽  
Sampling Frequency ◽  
Peak Picking ◽  
Signal To Noise ◽  
Zero Crossing ◽  
Software Implementations

Voice perturbation measures, such as jitter and shimmer, depend on accurate extraction of fundamental frequency (F o ) and amplitude of various waveform types. The extraction method directly affects the accuracy of the measures, particularly if several waveform types (with or without formant structure) are under consideration and if noise and modulation are present in the signal. For frequency perturbation, high precision is defined here as the ability to extract F o to ±0.01% under conditions of noise and modulation. Three F o -extraction methods and their software implementations are discussed and compared. The methods are cycle-to-cycle waveform matching, zero-crossing and peak-picking. Interpolation between samples is added to make the extractions more accurate and reliable. The sensitivity of the methods to different parameters such as sampling frequency, mean F o , signal-to-noise ratio, frequency modulation, and amplitude modulation are explored.

scholarly journals Reduction of Influence of the High-Frequency Noise on the Results of Surface Topography Measurements

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 333
Author(s):  
Przemysław Podulka
Keyword(s):  
Surface Topography ◽  
High Frequency ◽  
Extraction Procedure ◽  
Frequency Measurement ◽  
Measured Data ◽  
Measurement Noise ◽  
Frequency Noise ◽  
Research Papers ◽  
Definition Of ◽  
Processing Errors

The influence of errors in the processes of detection and then reduction of surface topography measurement noise is of great importance; many research papers are concerned with the definition of this type of measurement error. This paper presents the influence of high-frequency measurement noise, defined for various types of surface textures, e.g., two-process plateau-honed, turned, ground, or isotropic. Procedures for the processing of raw measured data as a detection of the high-frequency errors from the results of surface topography measurements were proposed and verified (compared) according to the commonly used (available in the commercial software of the measuring equipment) algorithms. It was assumed that commonly used noise-separation algorithms did not always provide consistent results for two process textures with the valley-extraction analysis; as a result, some free-of-dimple (part of the analyzed detail where dimples do not exist) areas were not carefully considered. Moreover, the influence of measured data processing errors on surface topography parameter calculation was not comprehensively studied with high-frequency measurement noise assessments. It was assumed that the application of the Wavelet Noise Extraction Procedure (WNEP) might be exceedingly valuable when the reduction of a disparate range of measured frequencies (measurement noise) was carefully considered.

scholarly journals Laser frequency counting and frequency modulation width measurement from a fft signal

2012 ◽  
Vol 19 (3) ◽  
pp. 565-572
Author(s):  
Petr Křen
Keyword(s):  
Frequency Modulation ◽  
High Frequency ◽  
Frequency Synthesizer ◽  
Signal To Noise Ratio ◽  
Frequency Measurement ◽  
Laser Frequency ◽  
Optical Frequency ◽  
Frequency Stabilized Laser ◽  
Frequency Counting ◽  
Fft Analysis

Abstract A new method of optical frequency beat counting based on fast Fourier transform (FFT) analysis is described. Signals with a worse signal-to-noise ratio can be counted correctly comparing to the conventional counting method of detecting each period separately. The systematic error of FFT counting below 10 Hz is demonstrated and can be decreased. Additionally the modulation width of a frequency-stabilized laser with high frequency modulation index can be simultaneously measured during a carrier frequency measurement against an optical frequency synthesizer or other laser.

Evaluation of the Time Varying Gravity Fields from GRACE Follow-On LRI Instrument

2020 ◽  
Author(s):  
Nadege Pie ◽  
Mark Tamisiea ◽  
Ben Krichman ◽  
Peter Nagel ◽  
Steve Poole ◽  
...  
Keyword(s):  
High Frequency ◽  
Signal To Noise Ratio ◽  
Gravity Models ◽  
Laser Ranging ◽  
Frequency Noise ◽  
Time Varying ◽  
Signal To Noise ◽  
Science Data ◽  
Design Concepts ◽  
Gravity Fields

<p>The Laser Ranging Interferometer (LRI) instrument on-board of the GRACE Follow-On (GRACE-FO) satellites has been collecting science data since a June 2018, a few weeks after launch. Though the LRI instrument, based on design concepts developed for a future LISA mission, was intended mostly as a demonstration instrument, it has far-exceeded its mission requirements and has provided intersatellite ranging observations with improved signal-to-noise ratio compared to the K-Band Ranging (KBR) instrument. The exploitation of the LRI observations has led to a set of monthly gravity field solutions comparable in many ways to the ones obtained from KBR. Though the ranging observations from the LRI have a much lower high-frequency noise content, this has not so far led to an improvement of the time-varying gravity estimates in the spatial domain, while stark differences are visible in the spectral domain between the KBR and LRI fields. We present the series of LRI gravity models in comparison to its KBR counterpart, as well as regional intercomparisons of the gravity solutions against hydrology models.</p>

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