调制传递函数(MTF)是评价CCD相机成像系统质量的重要参数，它能真实地反映相机拍摄时的空间频率与图像对比度的关系。CCD相机的MTF测试中最关键的是靶标的选择，它决定了整个系统的测量精度和操作过程的复杂程度。理想的靶标函数是正弦函数，但制作光出射度随正弦波规律变化的分辨率板是非常困难的，因此利用明暗相间、相互平行的黑白条纹分辨率板来代替正弦波分辨率板，提出了测量MTF的方法。重点对CCD相机在奈奎斯特频率处的MTF测试结果进行了分析与评价。

Modulation transfer function (MTF) plays an important role in the CCD camera imaging system. It indicates the relation between spatial frequency and image contrast. In the MTF measurement experiment, the choosing of the test board is the key. The measurement accuracy of the system and the complexity of operating procedure strongly depend on it. Although the ideal function of the test board is sine function, it is difficult to make up the sine test board. In order to solve this problem, the testing method of MTF is introduced, in which the sine test board is replaced by the resolving power test target consisting of parallel dark and bright stripes alternately. The MTF of CCD camera is examined at the Nyquist frequency and the results are analyzed and evaluated in detail.