Attitude metrology based on the field-of-view effect of birefringence using high-speed polarimetry.

ABSTRACT

A novel, to the best of our knowledge, optical method using a high-speed polarimetry is proposed for real-time attitude tracking in an ultra-large measurement range. The attitude metrology utilizes the field-of-view effect in birefringent crystals, which is known as the birefringence deviates with the field-of-view angle of polarized light. The basic principle of the metrology is presented via theoretical derivation and has been verified in the static retardance measurement experiments. With a resolution test, a temporal resolution of 0.4 ms per attitude measurement and an angular resolution up to 0.0025°are achieved. With the help of a bubble level, the attitude angles of an object attached with a birefringent wave plate are obtained in the dynamic experiments, which have achieved an accuracy better than 0.02°. Additionally, the angular velocity and acceleration of the real-time measured roll angle can be extracted simultaneously. The experimental results demonstrate that the proposed metrology has great potential and advantages in the real-time attitude sensing.