Precise aeronautical ground based navigation using LDACS1

In order to cope with the increasing demand for communication capacity in the aeronautical sector, the Future Communications Infrastructure is currently being developed. For air-ground communications two candidates are considered as the new L-band digital aeronautical communication system. In this paper, the idea of using one of these systems, namely LDACS1, as navigation aid is presented. Compared to satellite based navigation systems, LDACS1 exhibits a significantly lower vulnerability to intentional or unintentional interference. This is due to its larger received power. Despite LDACS1's general fitness to perform positioning, so far no precise ranging algorithm has been adopted. The standard LDACS1 synchronization procedure offers a simple ranging possibility, however, with restricted accuracy. Therefore, in this paper two newly adopted algorithms for determining precise range estimates between the aircraft and the ground station are presented. This also includes an assessment of the theoretical and currently achievable ranging precision. It is shown that the two algorithms offer a superior performance to the previously employed synchronization procedure.