讨论了干涉合成孔径雷达（InSAR）成像处理中基线解相关系数的频率函数，分析了在距离向压缩过程中频谱窗函数对InSAR图像对相关性的影响，通过定义干涉图距离向幅度谱函数的等效带宽来描述地形起伏，推导出了等效带宽和InSAR图像对相关性之间的关系式。据此给出了在不同等效带宽情况下（相当于不同地形起伏条件下），固定带宽滤波对InSAR图像对相关性的影响。最后的实验结果验证了上述分析的正确性。

This paper discusses the spectrum function of InSAR baseline decorrelation coefficient, and analyzes the effect of weighting function to InSAR baseline decorrelation coefficient in the procedure of range compression. And the equivalent bandwidth of interferogram spectrum in range direction is defined. Based on the estimated value of the equivalent bandwidth of interferogram spectrum in range direction, the relation between the equivalent bandwidth of interferogram spectrum in range direction and InSAR baseline decorrelation coefficient can be deduced. So the effect of fixed bandwidth filtering upon the coherence of the InSAR images could be quantitatively analyzed. At last of this paper, the experimental results using X-SAR data illustrate the validity of the analysis.