Research on alternative positioning navigation and timing in Europe

Evaluation of Alternative Navigation, Positioning and Timing Systems Based on Their Performance and Additional Characteristics

“…The last system focused on the use of the existing infrastructure is improvements to the DME system which has already had a large number of ground stations located around the world and their modernization is considered more feasible than in case of Mode N or eLORAN. [3]…”

“…Similarly to the ground equipment, the LDACS on-board avionics should be based on the current VDL equipment resulting in a multi-mode LDACS/VDL radio combined in a single avionics box [4]. In case of the DME system modernization, only the faster rise pulse could affect the on-board equipment change, and Multi-DME on the avionics software upgrade [3]. The advantage of the DME is that almost every aircraft is equipped by an on-board DME interrogator which is considered a prerequisite for facilitating the implementation.…”

“…This paper deals with evaluation of the different solutions from the performance point of view including additional features useful by implementation of the systems. The assessed systems considered APNT candidates in European region, mostly developed within Single European Sky ATM Research (SESAR) projects [3], specifically L-band Digital Aeronautical Communication System (LDACS), enhanced LOng-RAnge Navigation (eLORAN), improvements of Distance Measuring Equipment (DME) and Mode N.…”

“…Mode N uses the data transmission formats based on the Mode S specification in order to transmit information about location of the ground station in WGS-84 coordinates, antenna height, signal transmission time, station identification number or station status information [7]. SESAR project also proposes usage of DME upgrades for the APNT considered currently the short-term solution [3]. Firstly, DME Hybrid ranging may use one-way mode which is built on the existing ability of the DME to transmit pulse pairs without interrogation used for position update, and two-way mode used for periodic synchronization between aircraft and DME ground station.…”

“…Nevertheless, faster pulse rise time has a strong influence on the signal spectrum load and increase an adjacent channel interference. Finally, the Multi-DME al-gorithm upgrade focuses on providing on-board performance monitoring and alerting of undetected failure, in order to meet the (Required Navigation Performance) RNP requirements [3].…”