光学学报, 2017, 37 (4): 0430003, 网络出版: 2017-04-10
测风非对称空间外差干涉仪绝对相位漂移分析及校正
Absolute Phase Drift Analysis and Correction of Asymmetric Spatial Heterodyne Interferometer for Wind Detection
光谱学 非对称空间外差干涉仪 风场探测 干涉图 绝对相位漂移 校正 spectroscopy asymmetric spatial heterodyne interferometer wind detection interferogram absolute phase drift correction
摘要
多普勒非对称空间外差干涉仪可用来探测氧气大气带气辉谱线的多普勒频移,进而反演中高层大气的风速。由风速变化引起的干涉条纹相位频移十分微小,而由系统误差导致的绝对相位漂移会严重影响风速反演精度。双臂式干涉仪与单臂式不同,除受扩视场棱镜和光栅影响之外,用于产生光程差的空气隔片的热膨胀也会影响干涉图的绝对相位。通过实测和仿真计算不同温度下的绝对相位漂移,分析了绝对相位漂移的原因。在此基础上,提出了一种绝对相位漂移校正方法,通过求零风速和某一给定风速下两条线性相位拟合曲线之间的距离,校正温度引起的绝对相位漂移,从而准确反演风速。结果表明,仿真分析与实测的绝对相位漂移具有较好的一致性。校正绝对相位漂移后反演的风速误差为3.5 m/s,与校正前相比风速反演误差得到了极大的改善。
Abstract
A Doppler asymmetric spatial heterodyne interferometer can be used to detect Doppler frequency shift of airglow spectrum lines of the O2 band, and thus the wind speed in the high-level atmosphere can be retrieved. The absolute phase frequency shift of interference fringes caused by wind speed is small, and the absolute phase drift caused by system error has significant influence on the wind retrieval precision. Different with the single arm interferometer, the dual-arm interferometer has the absolute phase of its interferograms affected not only by the field-widened prisms and gratings, but also by the thermal expansion of spacers used to produce optical path difference. Therefore, the absolute phase drifts at different temperatures are measured experimentally and simulated numerically, and the reason of absolute phase drift is analyzed. Based on this, a absolute phase drift correction method is proposed. The distance between two linear phase fitting curves under the conditions of zero wind speed and a given wind speed is calculated, the temperature dependent absolute phase drift is corrected, and the wind speed is retrieved accurately. Results show that the measured phase drift fits well with the simulated phase drift. After the absolute phase drift correction, the retrieved wind speed error is 3.5 m/s, which is greatly improved compared with the result before absolute phase drift correction.
沈静, 熊伟, 施海亮, 罗海燕, 李志伟, 胡广骁, 方雪静, 徐标. 测风非对称空间外差干涉仪绝对相位漂移分析及校正[J]. 光学学报, 2017, 37(4): 0430003. Shen Jing, Xiong Wei, Shi Hailiang, Luo Haiyan, Li Zhiwei, Hu Guangxiao, Fang Xuejing, Xu Biao. Absolute Phase Drift Analysis and Correction of Asymmetric Spatial Heterodyne Interferometer for Wind Detection[J]. Acta Optica Sinica, 2017, 37(4): 0430003.