Improving the Availability of LDACS-Based APNT with Air-to-Air Ranging

Kurzfassung

The currently envisioned plan for Alternative Position, Navigation, and Timing (APNT) relies heavily on Distance Measuring Equipment (DME) for providing RNAV/RNP services. Alternative proposals include the use of L-Band Digital Aeronautical Communications System (LDACS) signals as a means of obtaining ranging measurements, relative to a network of ground stations. We extend the LDACS-based approach to include the Air-to-Air (A2A) Communications capability, which has been specified for future implementation. Using A2A distance measurements between aircraft, potentially extends the availability of APNT. This is particularly interesting for lowaltitude users (e.g. non-precision approach, departure) in the vicinity of high-altitude (e.g. en-route) users.