Application of α-β-γ filtering to real-time atmosphere methane concentration measurement

作者：Kan Rui Feng^*; Liu Wen Qing; Zhang Yu Jun; Liu Jian Guo; Chen Dong; Wang Min

来源：Chinese Physics, 2006, 15(6): 1379-1383.

DOI：10.1088/1009-1963/15/6/042

• Harmonic detection
• Multi-pass cells
• Real time filters
• Tunable diode laser absorption spectroscopy

A real time α-β-γ filtering technique is applied to the monitoring of atmosphere CH4 based on a tunable diode laser spectrum system operating at 1.654 μm. This technique is developed for improving the sensitivity and precision of CH4 concentration measurement with slow concentration change. The effectiveness of this technique is evaluated by performing CH4 concentration measurement and using it to monitor the varying methane level in the atmosphere. It was proved that signal noise ratio enhancement factor is 4.25. The comparison between this filter and moving average is also included in this article. It indicates the advantage of the α-β-γ real time filter.

• 出版日期2006