A concept for a ground-based navigation system to provide navigation service by substituting DME

• • A single frequency channel solution which requires much less spectrum than specified for DME/TACAN
• • ICAO PBN compatible, serves civil and military as well as unmanned aircraft

A frequency agile multi-mode aircraft system for the entire L-Band

• • DME/TACAN substitution, but emulates DME/TACAN in parallel to Mode N
• • Enables operation in a pure DME/TACAN or a mixed DME/Mode N or a pure Mode N environment
• • Mainly passive aircraft system, limited interrogation activity e.g., when required for data integrity and security reasons or to emulate DME
• • Low spectrum load in active mode realized by a sophisticated output power management

Aircraft position is calculated by using TDOA (reverse MLAT) and/or slant range measurements to ground stations in radio line of sight

Use of SSR Mode S signal formats and principles

• • Signal structure provides much better accuracy compared to DME
• • SSR/Mode signal format is already standardized by ICAO and Industry