This thesis presents a design and implementation of a long-range communication subsystem for a UAV and a ground control station. The subsystem is a low-cost alternative employing a line of sight, local communication network for optimal communications between a low-altitude UAV and a portable ground control station. In this thesis, real world experiments are conducted to model the time-variant wireless channel between a low-altitude micro-UAV and a portable ground control station operating in an urban environment. The large-scale and small-scale fading coefficients are calculated and analyzed for this dynamic channel. The channel properties, along with the fading distribution parameters, are computed and analyzed for two most popular antenna configurations for UAV systems (Yagi to omnidirectional and omnidirectional to omnidirectional). For the Yagi-to-omnidirectional link, the effects of three major impacting factors i.e. propagation distance, antenna gains in specific spherical angles and polarization mismatch factor on the overall fading distribution is investigated. Through regression analysis, a multiple-regression model is derived that estimates the instantaneous fading parameter, given these channel conditions. For this model, a modified particle-swarm optimization algorithm is designed and implemented to estimate the underlying model coefficients, given the instantaneous fading information. The implementation of this algorithm, along with the regression model, demonstrates that a sufficient approximation of the fading parameter can be provided for any given wireless channel when the impacting factors and instantaneous fading information is available. / February 2016

Unmanned aerial vehicles can be used in many different situations such as, for example, monitoring the growth of crops or for surveillance of a private property. Operating the unmanned aerial vehicle is usually done using some kind of ground control station. This thesis examines the possibilities of creating ground control stations working on several different platforms using the cross platform development frameworks Xamarin, Universal Windows Platform and Mono. This is done by creating and comparing three prototype applications regarding functional requirements, code reuse and resource usage. It is shown that none of the cross platform frameworks can fulfill all of the initial requirements on a ground control station. However, for the case studied in this thesis, Xamarin is demonstrated to be the most suitable cross platform framework of the three since it provides the same functionality as UWP for Windows devices while also enabling development for both Android and iOS devices.