遥感相机焦面CCD机械拼接中重叠像元数的确定

针对推扫式遥感相机前后摆成像中焦面拼接的CCD其像片间出现视场漏缝的问题,提出了一种焦面CCD的非均匀重叠像元数机械拼接方法.首先,构造了相机前后摆的成像原理模型；接着,分析了CCD间产生地面视场漏缝的原因,并依据模型推导出相机前摆和后摆时各CCD视场间漏缝大小的数学公式,从而得到各片间容许的最少重叠像元数量公式.在此基础上,进一步给出了后续电子学图像拼接与配准中片间重复像元数的函数形式,为实现图像无缝拼接提供了软件实现依据.分析表明,该方法的理论误差ε小于一个像元尺寸,即|ε/D|＜1.最后,给出了工程应用实例.

Computation of overlapping pixels of mechanical assembly CCD focal planes in remote sensing cameras

According to the imaging gaps caused by scrolling imaging in the conventional assembled focal plane for a push-broom camera,a mechanical assembling method with uneven overlapping pixels was proposed.Firstly,a model was established to simulate the imaging process when the camera was scrolled.Then,the reason that the gaps appear was analyzed,and a mathematical formula for the gaps between the CCD viewing fields at a certain scrolling angle was derived.Accordingly,the allowable minimum quantity of the overlapping pixels between every two CCDs was derived as well.On these bases,a function of overlapping pixels of images was given for subsequent software programs to eliminate the superfluous pixels and to realize the gapless assembly.Analysis indicates that the error ε of this assembling method is less than one pixel,which satisfies |ε/D|<1.Finally,an example was given.