空间外差光谱技术是应用于天文测量以及大气遥感等方面的一种超光谱分析技术。为消除应用过程中的基线漂移, 提出了改进的小波变换进行基线校正的方法。通过对不同小波函数以及分解层数对基线校正结果影响的分析, 对原始光谱信号进行小波分解得到细节系数和逼近系数, 将逼近系数置零以实现光谱信号的重构, 从而实现干涉图的基线校正。最后将小波校正结果与阈值拟合校正结果进行对比。结果显示: 两种方法校正光谱的相关系数为0.999 9, 结果一致, 但小波变换的程序运算耗时缩短10余倍。说明利用小波变换进行空间外差干涉图基线校正是一种行之有效、省时、简便的方法。

Spatial heterodyne spectroscopy(SHS) is a new spectroscopic technique which applies to astrometry and atmospheric remote sensing. A method of using wavelet transform to correct the baseline was proposed to eliminate the baseline drift during its application. Through the analysis of the influences of the different wavelet functions and decomposition layers on the results of baseline correction, the original spectrum was decomposed by wavelet transforms to get detail coefficients and approximate coefficients, and set the approximate coefficients to zero, the spectrum was reconstituted to realize the baseline correction. In the end, the results were compared with the results of the threshold fitting correction. The results show that the correlation coefficient of the two methods is 0.999 9 and the results are consistent, but the method of wavelet transform is more than ten times the time of the procedure. It is proved that using wavelet transform to carry out the baseline correction of spatial heterodyne interferometry is an effective, time saving and convenient method.