大气风场探测多普勒差分干涉仪相位稳定性影响因素分离测试方法

Separating and Testing Method for Influencing Factors of Phase Stability of Doppler Asymmetric Spatial Heterodyne Interferometer for Atmospheric Wind-Field Detection

多普勒差分干涉仪基于一种新型中高层大气风场探测系统,通过计算干涉图相位变化量反演观测目标源光谱的多普勒频移,实现大气风场测量。基准相位作为确定风场多普勒频移量的必要参数,其稳定性是保证风速测量精度的核心指标之一。针对非对称量相位漂移、相位斜率漂移和干涉图相位漂移这三项影响干涉仪基准相位的因素开展研究,基于多普勒差分干涉原理对其相位热漂移开展了理论分析,提出了各项因素相位漂移量的分离测试方法,并基于近红外多普勒差分干涉仪开展了实验测试。环境温度波动为0.27℃时,相位斜率变化量为670 mrad/m,干涉图相位漂移波动范围为8.9 mrad;修正干涉图相位漂移后,非对称量相位漂移约为4.7 mrad,均方根为0.98 mrad,等效风速测量误差为0.81 m/s。通过温度拉偏实验,得到非对称量相位漂移随温度的变化率为-493 mrad/℃的结论。

The Doppler asymmetric spatial heterodyne interferometer,a new type of mid-and upper-atmospheric windfield detection system,can achieve atmospheric wind-field measurement by the inversion of the Doppler shift of observed source spectra after calculating the changes in interferograms.The reference phase is a necessary parameter to determine the Doppler shift of the wind field,and its stability is one of the core indicators to ensure the accuracy of wind speed measurement.This paper investigates three factors that affect the reference phase of an interferometer,namely,the phase drift of asymmetric quantities,phase slope drift,and phase drift of interferograms.Moreover,the theoretical analysis of the thermal phase drift is carried out on the basis of the principle of Doppler asymmetric spatial heterodyne interference.The separating and testing method for the phase-drift quantities of each factor is proposed,and the experimental test is conducted by the near-infrared Doppler asymmetric spatial heterodyne interferometer.Under the ambient temperature fluctuation of 0.27℃,the change of phase slope is 670 mrad/m,and the phase-drift fluctuation range of interferograms is 8.9 mrad.Upon the phase-drift correction of interferograms,the phase drift of asymmetric quantities is about 4.7 mrad,and the root mean square is 0.98 mrad,with the equivalent wind speed measurement error of 0.81 m/s.According to the bias experiment on temperature,the rate of phase-drift change of asymmetric quantities with temperature is−493 mrad/℃.