The remainder of this thesis is structured as follows. Chapter \ref{chap:relatedwork} surveys existing indoor localization approaches related to this thesis. In Chapter \ref{chap:methods}, the developed texton-based approach is presented and its components, the \(k\)NN algorithm and the particle filter, are introduced. Details about the synthetic data generation tool and map evaluation technique are also given. Chapter \ref{chap:analysis} describes the setup of the on-ground and in-flight experiments. The results of the experiments are presented in Chapter \ref{chap:results} and discussed in Chapter \ref{chap:discussion}. Finally, we draw our conclusions and indicate future research directions in Chapter \ref{chap:conclusion}.