摘要
多普勒差分干涉光谱仪是傅里叶变换型光谱仪,在大气风速反演过程中,偶延拓的反演光谱无法直接解出目标谱线的相位,而且在实际测量中反演光谱中含有的杂散光谱线、噪声等,使得复干涉图相位发生变化,最终导致反演风速值的偏差。所以,在对实际噪声环境下测得数据的处理过程中,获取反演光谱相位信息时需要对目标谱线进行提取。针对不同信噪比的干涉图,利用蒙特卡罗方法对不同线宽的不同窗函数的优化反演结果进行分析。结果表明:对于信噪比高于26.5dB的干涉图,线宽为4~5倍光谱分辨率的高斯窗函数是最优的窗函数优化方式;对于信噪比低于26.5dB的干涉图,线宽为7~12倍光谱分辨率的矩形窗函数的反演风速值更精确,是最优的窗函数优化方式,可以复原相位信息,反演出大气风速的近似值。
Doppler difference interference spectrometer is a kind of Fourier transform spectrometer. In the process of atmospheric wind velocity retrieval, even-prolongated recovered spectrum cannot work out the phase information of the target spectral line directly. Meanwhile, there are stray spectral lines and noises in the recovered spectrum, which make the phase of the interferogram changed and the retrieved wind velocity deviated. Therefore, isolation of the target spectral line is necessary in the process of getting the phase information of the recovered spectrum in actual noisy environment. For interferograms with different signal noise ratios the retrieved wind velocities （SNR） optimized by different window functions with different line widths are analyzed by Monte-Carlo method. The results indicate that the Gaussian window function with line width equaling 4 to 5 times of the spectral resolution provides the best performance if the SNR of the measured interferogram is higher than 26.5 dB, and rectangular window function with line width equaling 7 to 12 times-of the spectral resolution provides the best performance if the SNR of the measured interferogram is lower than 26.5 dB. The phase information and the approximative atmospheric wind velocity can be retrieved.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2017年第2期84-90,共7页
Acta Optica Sinica
基金
国家自然科学基金(41005019)
关键词
信号处理
光谱数据反演
蒙特卡罗方法
大气风场探测
多普勒差分干涉仪
signal processing
spectral data retrieval
Monte-Carlo method
atmospheric wind field measurement
Doppler difference interference spectrometer
