Processing Unit of a Correlation Tracking System Based on an RTAI Real-Time Operating System

We used an adaptive optics system (to achieve tilt correction) in Lunar Laser Ranging.After describing in detail the principle of the correlation tracking for adaptive optics system,we present a wavefront processor based on the real-time operating system RTAI for correlation tracking.To achieve real-time processing of wavefronts,this wavefront processor adopts the absolute difference algorithm,a general-purpose CPU,and a Linux hard real-time extension system RTAI.As shown by experiments this processor is capable of computing 1 K frames per second for the correlation tracking and has the advantages of high integrity,good upgradability,and strong potential for extension.