Study on high speed dual-frequency laser interferometry in two longitudinal modes

2007 ◽  
Author(s):  
Tao Zhang ◽  
Chunsheng Yang ◽  
Wanfu Dong ◽  
Bin Wu
Keyword(s):  
High Speed ◽  
Laser Interferometry ◽  
Dual Frequency ◽  
Longitudinal Modes ◽  
Frequency Laser

Study on Doppler Velocity Measurement System

2012 ◽  
Vol 562-564 ◽  
pp. 1240-1243
Author(s):  
Jian Chao Li ◽  
Jun Hong Su ◽  
Ming Gao
Keyword(s):  
Measurement System ◽  
Velocity Measurement ◽  
High Speed ◽  
Processing System ◽  
Measurement Range ◽  
High Accuracy ◽  
Laser Doppler ◽  
Doppler Velocity ◽  
Dual Frequency ◽  
Frequency Laser

In order to satisfy the high accuracy velocity measurement requirement, using the improved dual-frequency laser Doppler velocity measurement principle, designed a set of laser Doppler velocity measurement system. System consists of two parts: optical system and signal acquisition and processing system. Through the establishment of dual-frequency laser Doppler velocity measurement experimental platform for testing, the result shows that the method can be carried on the high accuracy velocity measurement which in high speed move object. Measurement range from 0.1 m/s to 50 m/s, the error is less than 2 percent and it could increase the speed measurement range.

A Measuring Method of Track Irregularity for High-Speed Railway Based on Dual-Frequency Laser Interference Technique

2013 ◽  
Vol 552 ◽  
pp. 446-451
Author(s):  
Wen Jun He ◽  
Yue Gang Fu ◽  
Yang Zheng ◽  
Lei Zhang ◽  
Jia Ke Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Reference Method ◽  
Measuring Method ◽  
Dual Frequency ◽  
Laser Interference ◽  
High Speed Railway ◽  
Laser Alignment ◽  
Track Irregularity ◽  
Frequency Laser ◽  
Ray Path

A new measuring method of track irregularity for high-speed railway is proposed by using dual-frequency laser interference technique. The linear deviation between the phase-locked gauging head and the center line of the railway route can be calculated by comparing the phase difference variation of the laser beat signal in the test ray path and the reference ray path when the portable track inspection car is moving forward along the track. While we use laser ranging technique to measure gauge, after processing data, the static irregularity of track will be acquired by changing straightness deviation of phase-locked gauging head into straightness deviation of left-right two tracks. The method is different from the existing techniques for detecting high-speed railway irregularity, such as the inertial reference method, the measuring method of chord and the method of laser alignment; it utilized the accuracy of the time to accomplish the high-precision measurement of the space and achieved innovation in theory.

Measurement of Air Refractive Index Based on Surface Plasmon Resonance and Phase Detection by Dual-Frequency Laser Interferometry

2013 ◽  
Vol 40 (1) ◽  
pp. 0108001 ◽  
Author(s):  
陈强华 Chen Qianghua ◽  
罗会甫 Luo Huifu ◽  
王素梅 Wang Sumei ◽  
王锋 Wang Feng ◽  
陈新华 Chen Xinhua
Keyword(s):  
Refractive Index ◽  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Laser Interferometry ◽  
Phase Detection ◽  
Dual Frequency ◽  
Frequency Laser

Corner-Expansion Flow of Ionized Argon

1971 ◽  
Vol 49 (21) ◽  
pp. 2671-2679 ◽  
Author(s):  
O. Igra ◽  
I. I. Glass
Keyword(s):  
Room Temperature ◽  
Electron Number Density ◽  
Laser Interferometry ◽  
Total Density ◽  
Number Density ◽  
Dual Frequency ◽  
Electron Number ◽  
Recombination Rate Constant ◽  
Initial Shock ◽  
Frequency Laser

The recombination rate constant for ionized argon as a function of temperature was determined by using dual-frequency laser interferometry to measure total density and electron number density in a 15° corner-expansion flow. The flow was induced by a normal shock wave in a 4 in. × 7 in. (10.2 cm × 17.8 cm) hypervelocity shock tube over a range of initial shock Mach numbers [Formula: see text] and pressures [Formula: see text] Torr at room temperature T1 ~ 300 °K, with impurity levels less than 150 parts per million.

A Precision Dual-Frequency Laser Interferometer for High Speed Target

2008 ◽  
Vol 7 (2) ◽  
pp. 382-385 ◽  
Author(s):  
Sheng-Hua Lee ◽  
Tian-Syung Lan ◽  
Yu-Tang Chen ◽  
Shand-Dad Liaw
Keyword(s):  
High Speed ◽  
Laser Interferometer ◽  
Dual Frequency ◽  
Frequency Laser
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