Enhancing PBN Coverage with DME Optimization and Development

Performance Based Navigation (PBN) is fundamental to modern aviation, enabling precise and efficient aircraft operations by applying area navigation (RNAV) and required navigation performance (RNP) concepts. A key element of PBN is the reliance on ground-based navigational aids such as the DME equipment, which provide the positional accuracy necessary for operations in high-density airspace. This working paper investigates optimizing the PBN coverage by using the DME to DME concept and enhancing DME signal characteristics and range. Specifically, it evaluates the benefits and advantages of replacing the directional DME antennas traditionally co-located with the ILS with omnidirectional antennas. Such a configuration expands the range and uniformity of DME signals, addressing limitations in existing coverage and improving navigation reliability. The transition to omnidirectional DME antennas aims to support broader airspace utilization while maintaining compatibility with ILS operations. This approach could also align with initiatives to reduce the dependency on (D)VORs in remote areas or that already with the end of lifecycle (outdated). Through the coverage study and analysis, this working paper evaluates the effects of these changes on signal geometry, coverage gaps, and operational efficiency. Based on that, it is possible to compare coverage before and after to find out the extent of the expected benefit from this change, noting that this change may not require amending any of the current Instrument Flight Procedures (IFP). In order to achieve this goal, it requires rehabilitating and developing the current DME systems that are co-located with the ILS by changing some of the electronic boards and increasing the power amplifier. There are also some necessary civil works for the new antenna location. The findings suggest that adopting omnidirectional DME antennas enhances PBN performance by improving signal redundancy, more DMEs pairs, mitigating directional constraints, and enabling more seamless integration of RNAV procedures. These improvements contribute to a safer, more efficient, and globally harmonized air traffic management system.