Research On High Resolution And High Speed Laser Spot Detecting Technology Based On Bi-Linear CCD

The free space laser communication technology has an advantage of high speed, no disturbance and high security. The Acquire-Point-Track (APT) System which decides the performance of the free space laser communication is one most important subsystem of the Free Space Laser Communication System. The Fine Tracking System is a key part of the APT System. The precision of pointing and tracking, and the restraining of platform vibration are all depended on the Fine Tracking System in the end. It is a key technology of APT System to acquire the positon information of the spot at a high speed and high precision in Fine Track System as to control the fast steering mirror to calibrate the visual axis.In this paper, a design of bi-linear CCD laser spot detecting system was developed to acquire the spot position at a high speed and high resolution in APT Fine Tracking System. The laser spot was imaged both at X axis and Y axis by two linear CCDs through a composite optic system of spectroscope and cylindrical lens. The spot position signal of the two linear CCDs was converted to digital datas which were transferred into computer through USB2.0 high speed serial interface later. The spot centronic coordinates were acquired by software in the end. The sample rate of the two linear CCDs could reach to 3000frames per second and the detecting accuracy could reach to 0.8μrad as the Fine Tracking System required.