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DUFMAN – Dual Frequency Multipath Model for Aviation

The objective of the DUFMAN project was to build and validate multipath models for Galileo signals, in Single and Dual-frequency


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The objective of the DUFMAN project was to build and validate multipath models for Galileo signals, in Single and Dual-frequency. The models will be included into the Aviation standards, both in support of EGNOS and ARAIM services. The models are based on flight data collected from different aircraft types and different avionics antennas.

Contract Number: Call for Tenders No 635/PP/GRO/RCH/17/9877

Project Segment: Horizon 2020, Galileo Mission and Services evolution

Duration: May 2018 – January 2021

Budget: €1 606 597

Project Partners: German Aerospace Center, DLR (Germany), Airbus Operation Commercial Aircraft – Airbus Operations SAS (France), Airbus Defence and Space (Germany), Rockwell Collins (UK), Thales Avionics (France)

Project Coordinator:

Markus Rippl, DLR

(Markus [dot] Ripplatdlr [dot] de (Markus[dot]Rippl[at]dlr[dot]de))

European Commission Project Manager:

Matteo Sgammini (JRC-ISPRA)

(Matteo [dot] SGAMMINIatec [dot] europa [dot] eu (Matteo[dot]SGAMMINI[at]ec[dot]europa[dot]eu))

Juan Pablo Boyero Garrido

Juan-Pablo [dot] BOYEROatec [dot] europa [dot] eu (Juan-Pablo[dot]BOYERO[at]ec[dot]europa[dot]eu)



Galileo will contribute by means of its open service signals and/or in cooperation with other satellite navigation systems, to integrity-monitoring services aimed at users of safety-of-life applications in compliance with international standards. In this context, the EC has developed a roadmap for the evolution of the SBAS provided by EGNOS, including augmentation service for GPS L5, and for both Galileo E1 and E5a frequencies. Complementary to EGNOS, the Advanced RAIM (ARAIM) service will provide global integrity based on multiple satellite constellations, including GPS and Galileo, and dual-frequency on L1/E1 and L5/E5a signals.  

The European Commission and the European GNSS Agency are involved in standardisation activities in the frame, where the models developed in this projects will be included (notably on the Minimum Operational Performance Specification –MOPS- for Galileo and Dual-Frequency Multi-Constellation aviation services SBAS and ARAIM).


Project objectives

The European Commission launched the project to:

  • build and validate a dual frequency Galileo multipath model for aviation, including receiver noise and antenna group-delay variations, which will be a fundamental element to provide navigation services through ARAIM and SBAS dual frequency.
  • contribute to the preparation of the corresponding standards at the appropriate standardisation bodies.



The results of the DUFMAN project were:

  • The development and validation of a dual-frequency Galileo E1/E5a and GPS L1/L5 multipath model for aviation
  • The development and validation of a single-frequency Galileo E1, Galileo E5a and GPS L5 multipath models for aviation
  • The inclusion into the DFMC SBAS MOPS and SARPS standards of the proposed models for both Galileo and GPS
  • The development and validation of the multipath model during the smoothing filter transient phase for both time-variant and time-invariant filter
  • The prediction of multipath and group delay variation errors for different aircrafts, antenna configurations, and flight phases. The estimation is based on electromagnetic simulations making use of a characterization of the avionics antenna and the 3D model of the aircraft.
  • The dissemination activity of the project directed towards the scientific community and standardisation bodies. Within the project execution 12 conference papers and 1 journal paper have been published.


Expected impact

The DUFMAN project has derived multipath models for Galileo signals, in Single and Dual-frequency. Similar models have been developed for GPS, for combine use. The models have been validated with real data.

Furthermore, the project has contributed to the development of the future Aviation Standards for EGNOS and ARAIM, which now include the use of Galileo OS signals.

Disclaimer: The project results represent the views of the consortium. They do not necessarily represent the views of the European Commission and they do not commit the Commission to implementing the results.