探讨了在共焦成像算法中影响成像对比度的因素。首先指出,算法中时延估算的不准确是导致成像对比度下降的根本原因,并给出了共焦成像算法中时延误差与成像对比度之间的定量关系。作为对结论的验证,文中以在非均匀媒质中成像为例,探讨了媒质电磁参数的非均匀性与时延误差以及与成像对比度之间的关系。 The factors affecting the imaging contrast in the confocal imaging algorithm are discussed. First of all, it is pointed out that the inaccuracy of the delay estimation in the algorithm is the root cause of the decrease of the imaging contrast, and the quantitative relationship between the delay error and imaging contrast in the confocal imaging algorithm is given. In order to verify the conclusion, the paper takes the imaging in non-uniform media as an example to discuss the relationship between the non-uniformity and delay error of electromagnetic parameters and the imaging contrast.