调制传递函数（MTF）是高空间分辨率光学卫星相机的重要参数之一。提出一种基于周期靶标的直接检测方法，从遥感影像数据计算得到成像系统在奈奎斯特频率处的MTF值，同时利用参数化模型获取全频率的MTF曲线。试验结果表明，在均匀的暗背景上，沿遥感器的垂轨方向与顺轨方向上分别布设5组非整像素（地面像元分辨率）间隔的三线靶标，并在大面积靶标的配合下，可直接测得光学卫星相机的MTF值，检测误差优于5%，满足在轨检测的应用要求。

Modulation transfer function (MTF) is one of the important parameters of high-spatial-resolution satellite optical cameras. A new method for in-flight MTF measurement using periodic targets is presented. It can directly obtain the MTF value at Nyquist frequency and MTF plots by parametric model. The experimental results show that the satellite optical camera′s MTF can be directly and accurately acquired by deployment of five groups of non-integer pixel (ground sample distance) interval of three-bar targets in cross and along track directions respectively, and can be arranged with the large-area target in homogenous dark background. The error is less than 5% and the approach can satisfy the application requirements for spaceborne estimation.