The influence factors and optimization methods of the local oscillator power for coherent doppler lidar

• Published in: 2011 International Conference on Remote Sensing, Environment and Transportation Engineering pp. 2692 - 2695
• Main Authors: Zhichao Bu, Yinchao Zhang, Siying Chen, Zongjia Qiu, He Chen, Pan Guo, Shengzhe Chen, Xianying Ge
• Format: Conference Proceeding
• Language: Chinese; English
• Published: IEEE 01-06-2011
• Subjects: Laser radar; Local oscillators; Optical fiber sensors; Optical fibers; Optical mixing; optimum local oscillator power; range of echo signal; Signal to noise ratio; the relative intensity noise; the saturation effect of photoelectric detector
• ISBN: 9781424491728; 142449172X
• DOI: 10.1109/RSETE.2011.5964871

Coherent doppler lidar for wind is based on the heterodyne detection between local oscillator signal and the echo signal. Optimum optical local oscillator power is an important factor of the signal to noise ratio. The dynamic range of echo signal, the relative intensity noise and the photoelectric detector saturation effect are studied comprehensively as the local oscillator power influence factors for the first time. The expression of the local oscillator power and SNR is derived. Using the computer simulation, the conclusion that the dynamic range of the echo signal will not affect the optimum of the local oscillator is obtained. Selecting different values of the relative intensity noise, the curves of the SNR versus local oscillator are given. Comparing the SNR formula in the quantum limit with the derived SNR formula, the saturation effect of the photoelectric devices is studied.