Communication experiments of free space optical system which was laid on the vibration platform were implemented. In the communication experiments, the transmitting terminal is static and the receiving terminal is laid on the vibration platform. The vibration platform was used to validate the performance of the APT (acquiring, pointing and tracking) system. The analytic results of experimental data prove that the APT system can effective restrain the destabilization of laser beam caused by the vibration platform. The communication distance is 3.4 km and the communication rate is 2.5 Gbps.
Increasingly importance has been taken seriously for high frame rate CMOS camera to optical communication acquisition pointing and tacking (APT) system, with its compact structure, easy to developed and adapted to beacon light spot detection in atmospheric channel. As spot position accuracy directly determines the performance of space optical communication, it is very important to design a high precision spot center algorithm. Usually spot location algorithm uses gravity algorithm, shape center capturing algorithm or self-adaption threshold algorithm. In experiments we analyzed the characteristics of the spots which transmitted through atmospheric turbulence and studied light transmission characteristics in turbulent channel. We carried out a beacon light detection experiments in a distance of 3.4km, collected the beacon spots on CMOS camera and signal light power. We calculated spot position with two different algorithm and compared the calculation accuracy between field dispersive spot and ideal Gaussian laser spot. Experiment research show that, gravity center algorithm should be more suitable for beacon beam spot which accuracy can be improved about 1.3 pixels for a Gaussian spot. But the shape center algorithm has higher precision. The reasons were analyzed which made an important preparation for subsequent testing.