Fundamental Laser Beam Simulation for Space Applications

Kurzfassung

Optical Satellite Communication (OSC) is more precise, more efficient, and allows for more data to be transmitted than with the established radio technology. Furthermore, this technology represents the corner stone for any advancement to quantum communication in the future. Enough possible fields of application exist: Earth observation satellites collect ever more data and satellite communication networks become ever more present. But, not to few challenges come with OSC: With further miniaturization, as very small satellites, so-called CubeSats, are of great interest nowadays, arises the need for more sophisticated pointing and tracking systems, and atmospheric effects, as weather and turbulence, present themselves as issues. As many different approaches are being tested, this thesis is focused on low Earth orbit (LEO) satellites communicating with ground stations (stationary and transportable). A specifically developed simulation calculating the fundamental transmitter and receiver gain as well as the free space loss and adding it all up in the total gain was used to test different transmitters and receivers and, in the end, different communication setups. The primary takeaway is that one optimal setup cannot be found. A setup must be chosen according to ones needs. The main aperture and secondary mirror radius, short wave infrared and long wave infrared light, as well as transmitter and receiver distance were examined. From all of these the main aperture radius had the most significant impact on the overall form of the signal. From the comparison of the stated wavelengths another argument for long wave infrared light countering weather effects was made. Said distance mainly influence the free space loss and, with that, presented itself as a factor but not a mission defining one. In addition to all of this, the implementation of the used simulation as a Matlab Simulink block and integration into an orbit simulation is presented, as well as a possible pointing and tracking solution.