Lightweight, mobile free-space optical communications in disaster scenarios for transmission of Earth observation data: feasibility study

Free-space optical (FSO) links are an effective alternative to radio frequency (RF) to handle high-rate data transmission in case of a general communication service failure in disaster scenarios. Establishing high data rate links under the impacts of extreme environmental conditions, like the unregulated RF spectrum, is a very challenging issue. This paper focuses on multicopter (e.g., quadrocopter or hexacopter) based earth observation systems. Its main objective is to show that FSO communication can provide a high-rate link for transmitting earth observation data from a multicopter to a ground station, even under environmental disaster conditions. Before analyzing the feasibility of such an optical multicopter system, the main system structure will be discussed in detail. Several system designs will be compared and evaluated based on link budget calculations. In this process, a novel Grating Light Valve (GLV) retroreflector modulator technology will be introduced in this work. The study will emphasize that a reliable 100 Mbit/s FSO data transmission will be feasible to provide a downlink capacity for multicopter based earth observation systems.