Modeling of Fine Tracking Sensor for Free Space Laser Communication Systems

The optical communication networks comprised of ground stations, aircraft, high altitude platforms, and satellites become an attainable goal, however, some challenges need to be overcome. One of challenges involves the difficulty of acquisition, tracking, and pointing (ATP) a concentrated beam of light arriving from another platform across the far reach of space. To meet the pointing accuracy requirement, the basic method of tracking between the terminals of optical communication systems includes the use of a beacon laser and tracking system with a quadrant detector sensor on each terminal. In some future optical communication networks, it is plausible to assume that tracking system and communication receivers will use the same sensor. In this paper, the architecture of the fine tracking assembly of the designing optical communication terminal (OCT) is described, and the fine tracking assembly sensor is modeled based on the correlation coefficient. The simulation and experiment results of the sensor show that the detecting accuracy satisfies the design demand for our developing OCT. Keywords-modeling; quadrant detector; fine tracking sensor; optical communication networks