同步与数据缓冲系统的同步定时器

同步定时器是ＣＤＡＳＳ／ＤＢ系统的重要部件。它用高精度数字锁相环，精确地恢复地球同步气象卫星采集的原始云图数据的同步基准信息。数字锁相环由用高速器件组成的相位比较器和用计算机软件实现的滤波器构成，采用标准频率计数方式，完成对模拟太阳（ＳＰ）和数字太阳（ＳＳＤ）的锁相及卫星上时钟频率测量等任务。

Synchronous Timer for Synchronization/Data Buffer System

The Synchronous timer is used as a major Component of the CDAS S/DB System.It uses a high precision digital phase-locked loop(PLL) to accurately recover the Synchronous reference information of raw cloud-cover image data collected by the geostationary satellite.The PLL consists of the phase comparator implement by high speed IC and the filter by the comptuer software,and operates in the standard frequency count mode, hence measures SP and SSD phases locked and, the on-board clock frequency.