title: Time-frequency analysis for microwave reflectometry data processing in the HL-2A tokamak.
abstract: The Choi-Williams distribution (CWD) technique is introduced as a time-frequency tool for processing data measured from the new developed homodyne and the fixed frequency reflectometry in the HL-2A tokamak. The comparison between spectrogram and CWD for the simulated signal is presented. It indicates that the CWD can greatly improve the representation of the time-frequency content of the multi-components signal. Its effectiveness is demonstrated through two applications in HL-2A, which are the extraction of beat frequencies from the frequency modulated-continuous wave reflectometry (FM-CW) and the characterizing of the fluctuations. The density profile inversed from the group delay of the FM-CW and the density fluctuations deduced from the fixed-frequency reflectometry would be more reliable and accurate by using the CWD technique.
authors: Southwestern Institute of Physics, Chengdu 610041, People's Republic of China. zhongwl@swip.ac.cn
authors: W L
authors: WL
authors: Zhong
authors: Z B
authors: ZB
authors: Shi
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authors: XL
authors: Zou
authors: X T
authors: XT
authors: Ding
authors: X L
authors: XL
authors: Huang
authors: Y B
authors: YB
authors: Dong
authors: Z T
authors: ZT
authors: Liu
authors: W W
authors: WW
authors: Xiao
authors: X Q
authors: XQ
authors: Ji
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authors: Cui
authors: Yi
authors: Y
authors: Liu
authors: L W
authors: LW
authors: Yan
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authors: QW
authors: Yang
authors: X R
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authors: Duan