干涉图零光程差位置的确定方法

Correction method of zero path difference position

风云四号A星干涉式大气垂直探测仪在轨运行以来发现,受噪声、采样误差、条纹计数错误等影响,干涉图零光程点会发生定位偏差.干涉条纹平移引起的相位误差与波数成线性关系,对残余相位进行线性回归分析可以得到零光程差位置的偏移量.利用在轨实测数据,应用残余相位方法,分析了零光程点定位偏差校正前后对相位谱及辐射光谱的影响.该方法已经应用于风云四号A星干涉式大气垂直探测仪的在轨数据预处理中,并取得了很好的应用效果.

The Geostationary Interferometric Infrared Sounder（ GIIRS） on board FY-4A is a Michelson interferometer infrared sounder. The interferogram is sampled at discrete points. The zero path difference（ ZPD）,which is the peak of the interferogram,is not sampled. This effectively shifts the interferogram and adds a linear phase to the spectrum. A linear regression on the residual phase of the calibrated spectrum will reveal the shift. This method has been used in the interferogram signal processing of the GIIRS,and has obtained a better results.