Precision Determination of the Best Imaging Position of CCD Array of Space Camera with Optical Transfer Function

A measurement method of optical transfer function(OTF)is discribed in this paper,in which charge-coupled device(CCD)in space camera,with an image sampler joined up with a PC,is used directly as an optoelectronic element.Knife edge scanning with high precision and high sampling density and digital Fourier analysis method is adopted.After measuring the defocal MTF curve of space camer-a,the best imageing position is determined precisely.