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Analysis of photonic Doppler velocimetry data based on the continuous wavelet transform
Shouxian Liu1, Detian Wang, Tao Li
1Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang, Sichuan, People's Republic of China. pion55@163.com
The Review of Scientific Instruments
|March 3, 2011
Summary
The continuous wavelet transform (CWT) offers superior analysis of photonic Doppler velocimetry (PDV) data compared to the short-time Fourier transform (STFT). This new method accurately tracks rapid velocity changes, improving PDV data analysis.
Area of Science:
- Optics and Photonics
- Signal Processing
- Experimental Mechanics
Background:
- Photonic Doppler velocimetry (PDV) is crucial for measuring high-speed events.
- Traditional short-time Fourier transform (STFT) analysis struggles with rapid velocity changes in PDV data.
- Limitations in STFT hinder accurate interpretation of complex dynamic phenomena.
Purpose of the Study:
- To introduce a novel analysis method for PDV data using continuous wavelet transform (CWT).
- To overcome the limitations of STFT in resolving rapid velocity variations.
- To provide an accurate and adaptive approach for PDV signal processing.
Main Methods:
- Employed continuous wavelet transform (CWT) for adaptive time-frequency analysis.
- Utilized the wavelet family's adaptability to estimate instantaneous signal frequencies.
- Identified signal's local frequencies by locating the ridge in the CWT spectrogram.
- Converted local frequencies to velocity using Doppler principles.
Main Results:
- CWT demonstrated superior performance in analyzing PDV data compared to STFT.
- The CWT method accurately resolved rapid velocity changes observed in a plate-impact experiment.
- The developed technique proved to be automatic and suitable for PDV data analysis.
Conclusions:
- Continuous wavelet transform (CWT) is an effective and adaptive tool for PDV data analysis.
- CWT overcomes STFT's limitations in capturing transient velocity dynamics.
- This method enhances the accuracy and applicability of photonic Doppler velocimetry.
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