Lidar-Assisted Acquisition of Mobile Airborne FSO Terminals in a
GPS-Denied Environment
Abstract
For acquisition of narrow-beam free-space optical (FSO) terminals, a
Global Positioning System (GPS) is typically required for coarse
localization of the terminal. However, the GPS signal may be shadowed,
or may not be present at all, especially in rough or unnameable
terrains. In this study, we propose a lidar-assisted acquisition of an
unmanned aerial vehicle (UAV) for FSO communications in a poor GPS
environment. Such an acquisition system consists of a lidar subsystem
and an FSO acquisition subsystem: The lidar subsystem is used for coarse
acquisition of the UAV, whereas, the FSO subsystem is utilized for fine
acquisition to obtain the UAV’s accurate position. This study
investigates the optimal allocation of energy between the lidar and FSO
subsystems to minimize the acquisition time. Here, we minimize the
average acquisition time, and maximize the cumulative distribution
function of acquisition time for a fixed threshold. We learn that an
optimal value of the energy allocation factor exists that provides the
best performance of the proposed system.