Clean Sky


Modern weather radars on-board commercial aircraft first arrived around the 1950’s, with the intent to detect and avoid storms along the flight path. Since then, technology and performance have progressed tremendously. With the integration of wind-shear and turbulence detection, aircraft radars have grown into complex systems. At the same time, these systems have become extremely common. In April 2013, Rockwell Collins announced it had delivered its 20,000th air transport aircraft weather radar.

Most of today’s airborne weather radars operate in the X-band, whereas ground based weather systems usually operate in the S-band or C-band. In the realm of ground radars, dual-polarization technology is being introduced on these S-band and X-band systems, following extensive work by the NOAA and others. In 2013, all US-based NEXRAD ground weather radars were equipped with dual-polarization.

Dual-polarized weather radars offer clear advantages with respect to accuracy and versatility. With the merging of data from the two polarizations, the radar system will be able to establish differential reflectivity, correlation coefficients, linear depolarization and specific differential phase. These lead to better performance in detecting tornadoes, better rainfall prediction, precipitation types, icing detection and 3D-cloud build-up. In turn, these benefits will allow improved trajectory management.

However, airborne radar systems face much more stringent requirement and boundary conditions than their ground-based counterparts. This is particularly the case for the antenna. Further, dual-polarization has been demonstrated for other applications, but not for a nose-mounted set-up. The nose-mounted set-up for dual-polarized weather radar poses form-fit requirement that are extremely tight. Also weight, power and cost concerns pose a very significant economic issue particularly for the aviation environment.

From recent research and development in polarization, several promising technologies and solutions have come up as candidates for dual-polarized antennas.

In this proposal, we describe a work programme, subjected to the requirements described in the CfP, to conduct evaluation and selection of applicable antenna technologies/architectures, design and test of the best candidate up to TRL 4 (breadboard evaluation in laboratory environment), identification of a technological roadmap for future development up to the highest TRL levels.