F数是遥感CCD摄像机设计的关键参数 ,与其它重要参数关联度非常大 ,对摄像机的成像质量也有很大的影响。通过对动态范围、信噪比、传递函数、图像质量因子和焦深等参数在不同F数时结果的比较 ,说明F数的取值不是单调的 ,而是一个折中的过程。经论证认为F=4是比较合理的 F number is the key parameter of the remote sensing CCD camera design, and the correlation degree with other important parameters is very large, which also has a great influence on the imaging quality of the camera. Comparing the results of dynamic range, signal-to-noise ratio, transfer function, image quality factor and depth of focus with different F numbers shows that the value of F is not monotonous, but a compromise. It is argued that F = 4 is more reasonable