Safe flight on a rainy day
The EU-funded project X-WALD (Avionic X-band weather signal modelling and processing validation through real data acquisition and analysis) focused on the validation of algorithms used for the evaluation of meteorological conditions encountered in flight. The validation of the airborne radar signal simulator Cleosim was performed to exploit the potential of polarimetric radars in civil aircraft. In the past, such detectors were used only for navigation. Today, they can support detection of dangerous weather phenomena. Cleosim had been developed in the framework of the Clean Sky programme along with polarimetric radar signal processing and trajectory optimisation algorithms. The simulator can generate weather phenomena scenarios to test algorithm performance. During X-WALD, researchers collected real data in a well-monitored scenario to check the quality of simulator scenarios. For the measurement campaigns, two sites were selected: the Consiglio Nazionale delle Ricerche (CNR) building in Roma Tor Vergata in Italy and a small airfield close to the town of Apeldoorn in the Netherlands. Preliminary flight tests were carried under good weather conditions to ensure the correct function of an X-band polarimeter radar. Weather conditions were continuously monitored in search of suitable rain events, including convective and stratiform rainfall. Collected measurements were used together with ancillary data coming from polarimetric ground radars as well as meteorological sensors to crosscheck the results of data analysis. The uniqueness of such measurements added value to the X-WALD project. Importantly, the existing polarimetric radar signal simulator was extensively tested, validated and refined. Today, it represents a valuable tool in the hands of engineers designing polarimetric weather radar for both civil and military aircraft.
Keywords
Polarimetric radar, flight safety, X-WALD, Cleosim, Clean Sky
