电荷守恒与CCD孔径测光

Charge Conservation and CCD Aperture Photometry

Lick天文台的CCD控制器是一类新型控制器,它能够在同一CCD系统内实现MPP(Multi—pinned phase)和通常工作模式间的转换．自2002年起中国至少有4架 CCD照相机使用这类控制器．此控制器的弱点是溢出发生在非线性前,而且远在饱和以前．虽然这对亮的面光源观测不利,并且它妨碍了使用亮星构建点扩散函数(psf)．但是由于电荷守恒原理,对亮的点源(恒星)的孔径测光依然可行．观测证明了此结论．

The Lick Observatory＇s CCD controller is a new type controller, it provides the ability to switch between MPP （Multi-pinned phase） mode and normal operation with one CCD system. There are at least 4 CCD cameras using this type of controller in China since 2002. The weakness of this controller is that blooming occurs before nonlinearity and long before saturation. Though it is hard for extended source observation at high intensity level and it prevents applying bright stars to make point spread function （psf）, the aperture photometry for bright point sources （stars） is still feasible due to the principle of charge conservation. The conclusion is confirmed in this paper.