“…These may include Azimuth/Elevation (AZ-EL) gimbals, a Machine Vision Camera (MV CAM) that could either be visual or thermal cameras, and Near Infrared (NIR) cameras for coarse pointing, while the fine-tracking apparatus typically includes options such as Spatial Light Modulators (SLMs), Fast Steering Mirrors (FSMs), AZ-EL gimbals, Position Sensing Detectors (PSDs), MV CAMs, and NIR cameras. In a review of PAT approaches for UAV-assisted FSO relays, the author of [49] identifies conventional and asymmetric approaches, whereby in the conventional approach, the OGS and aerial platform both require mechanical gimbals to actively align the link, implying heavy hardware onboard the UAV, a setup better suited for larger platforms such as HAPs. Conversely, in an asymmetric approach, the UAV adheres to strict SWaP constraints and uses lightweight compact payload modules, thereby transferring the heavier mechanical gimbals and other PAT apparatus to the OGS.…”