| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of analyzing a pulse train generated as a result of particle monitoring in a scanning beam. SOLUTION: The signal processing method enhances a signal-to-noise ratio, and remarkably reduces an erroneous alarm rate for the particle. A noise pulse not generated by a scanner frequency is filtered because executed in a time domain. This analysis further identifies a particle-pulse envelope (PPE) by performing forward-directional and backward-directional autocorrelations (S248, S249). Gaussian fitting is applied thereafter to the identified particle-pulse envelope, to measure a particle characteristic such as a size and a speed. COPYRIGHT: (C)2008,JPO&INPIT
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