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Title: Singular value decomposition filtering for enhanced signal extraction from two-dimensional beam emission spectroscopy measurements

Abstract

The signal-to-noise ratio (SNR) of extracted turbulence features from beam emission spectroscopy (BES) data is significantly enhanced via application of singular value decomposition (SVD) methods. BES measures two-dimensional localized density fluctuations in DIII-D. The SNR of core turbulence characteristics is typically limited by noise arising from electronic noise, photon noise, and fluctuations in the observed neutral beam. SVD filtering has led to a significant enhancement in the SNR, reducing errors in time-resolved measurements of core turbulence characteristics, including correlation lengths, decorrelation rates, and group velocities. The SVD filtration technique is applied to BES data by combining multiple physically adjacent sampling locations to extract spatially correlated signals while partially removing unwanted incoherent noise. Using approximately half of the singular value weighted modes to reconstruct turbulence signals is found to improve SNR by up to a factor of 4, while maintaining the spatial structure of the turbulence. Unique aspects of application of SVD to broadband turbulence data are discussed.

Authors:
; ;  [1]
  1. University of Wisconsin, Madison, Wisconsin 1500 Engineering Dr., Madison, Wisconsin 53706 (United States)
Publication Date:
OSTI Identifier:
21266688
Resource Type:
Journal Article
Journal Name:
Review of Scientific Instruments
Additional Journal Information:
Journal Volume: 79; Journal Issue: 10; Conference: HTPD08: 17. topical conference on high-temperature plasma diagnostics, Albuquerque, NM (United States), 11-15 May 2008; Other Information: DOI: 10.1063/1.2979879; (c) 2008 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0034-6748
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BEAMS; DOUBLET-3 DEVICE; EMISSION SPECTROSCOPY; FLUCTUATIONS; NOISE; PHOTONS; PLASMA DENSITY; PLASMA DIAGNOSTICS; SIGNALS; SIGNAL-TO-NOISE RATIO; TIME RESOLUTION; TURBULENCE; TWO-DIMENSIONAL CALCULATIONS

Citation Formats

Shafer, M W, McKee, G R, and Schlossberg, D J. Singular value decomposition filtering for enhanced signal extraction from two-dimensional beam emission spectroscopy measurements. United States: N. p., 2008. Web. doi:10.1063/1.2979879.
Shafer, M W, McKee, G R, & Schlossberg, D J. Singular value decomposition filtering for enhanced signal extraction from two-dimensional beam emission spectroscopy measurements. United States. https://doi.org/10.1063/1.2979879
Shafer, M W, McKee, G R, and Schlossberg, D J. 2008. "Singular value decomposition filtering for enhanced signal extraction from two-dimensional beam emission spectroscopy measurements". United States. https://doi.org/10.1063/1.2979879.
@article{osti_21266688,
title = {Singular value decomposition filtering for enhanced signal extraction from two-dimensional beam emission spectroscopy measurements},
author = {Shafer, M W and McKee, G R and Schlossberg, D J},
abstractNote = {The signal-to-noise ratio (SNR) of extracted turbulence features from beam emission spectroscopy (BES) data is significantly enhanced via application of singular value decomposition (SVD) methods. BES measures two-dimensional localized density fluctuations in DIII-D. The SNR of core turbulence characteristics is typically limited by noise arising from electronic noise, photon noise, and fluctuations in the observed neutral beam. SVD filtering has led to a significant enhancement in the SNR, reducing errors in time-resolved measurements of core turbulence characteristics, including correlation lengths, decorrelation rates, and group velocities. The SVD filtration technique is applied to BES data by combining multiple physically adjacent sampling locations to extract spatially correlated signals while partially removing unwanted incoherent noise. Using approximately half of the singular value weighted modes to reconstruct turbulence signals is found to improve SNR by up to a factor of 4, while maintaining the spatial structure of the turbulence. Unique aspects of application of SVD to broadband turbulence data are discussed.},
doi = {10.1063/1.2979879},
url = {https://www.osti.gov/biblio/21266688}, journal = {Review of Scientific Instruments},
issn = {0034-6748},
number = 10,
volume = 79,
place = {United States},
year = {Wed Oct 15 00:00:00 EDT 2008},
month = {Wed Oct 15 00:00:00 EDT 2008}
}