过采样是为提高遥感扫描图像分辨率而提出的一种新的成像体制，为将其应用于红外搜索与跟踪系统，需研究过采样对系统点目标检测性能的影响。从扫描成像原理角度对比分析常规采样和过采样的特点；基于高分辨率图像退化方式给出扫描图像仿真方法；通过仿真扫描图像进行单帧目标检测处理，对比分析两种采样体制下的系统点目标检测性能。结果表明，在相同条件下，过采样系统点目标检测性能优于常规采样；常规采样扫描图像中目标一般呈现1×1点状，而过采样扫描图像中目标呈现斑点状，利用该特性可进一步提升过采样系统目标检测性能。

The over-sampling is a novel imaging scheme for improving resolution of remote sensing scanning images. If the scheme is employed by the infrared search and track system, it is necessary to analyze the effect of the over-sampling on the point target detection performance. The characteristics of over-sampling imaging are compared to those of the standard sampling with respect to the scanning imaging principle. Based on degradation of high-resolution image, a method of scanning image simulation is proposed. The scanning images including objects are simulated and processed by a typical single-frame target detection algorithm, and the detection performance of the two sampling schemes is analyzed. Experimental results show that under the same conditions, the point target detection performance of the over-sampling scheme is better than the standard sampling. The scanning image of standard sampling for target is generally a 1×1 point, while the over-sampling scheme creates pixel-clutter for target. The characteristic can improve the target detection performance further.