DATA-PROCESSING OF THE 2-CHANNEL ADAPTIVE STRAIGHTNESS MEASUREMENT SYSTEM BASED ON OPTICAL-ACTIVITY

In this paper the adaptive noise-cancelling technique (ANC) is applied in a two-channel straightness measurement system based on optical act ivity. The ANC technique may get rid of the correlated noise. in this system, one laser beam serves for monitoring the environment turbulenc e and the other is for measurement. Because the two beams are sufficie ntly close to each other, the condition of correlation is satisfied Th e experimental results show that the compensating effect is 30-80% aft er filtering. Theoretical and experimental results are given.