Beam Tracking for UAV-Assisted FSO Links With a Four-Quadrant Detector

A ground-to-air free-space optical link is studied for a hovering unmanned aerial vehicle (UAV) having multiple rotors. For this UAV, four-quadrant array of photodetectors used at the receiver to alleviate adverse effect fluctuations by enlarging field-of-view. Extensive mathematical analysis conducted evaluate beam tracking performance under random effects fluctuations. The accuracy derived analytical expressions corroborated performing Monte-Carlo simulations. It shown that such links depends heavily on and, each level instability there an optimal size minimizes error probability.