Practical considerations of optimal three-dimensional indoor localization

The problem of locating objects and people in indoor environments is lately gaining high interest in research and industry. In this context, the geometrical constellation of source and sensors plays an important role and heavily influences the accuracy for the position estimate. This paper uses existing optimal solutions of the problem of three-dimensional TDOA localization, and relates them to practical application. The extension is necessary, since the optimal solution is only valid for one single position and not for a complete area, where a localization capability is desired. Therefore, it is shown by simulations that the optimum is very useful for localization purposes in typical indoor scenarios. In addition, real-world measurements using an ultra-wideband (UWB) localization system have been carried out in two geometrical scenarios. It can be shown that the simulations, which are based on theoretical derivations, are a good approximation of the reality. Finally, it can be demonstrated that the optimal solution can be adapted to typical indoor environments and still yield accurate three-dimensional positioning