Comparing predicted and measured time-variant DVOR bearing errors in presence of wind turbines

Abstract

International audienceThe impact of scattering objects such as wind turbines (WTs) and other buildings on the VOR has beenaddressed in various publications. Nevertheless, a practically feasible possibility to predict especially the DopplerVOR bearing error during the building’s planning phase is challenging, since a electromagnetic model of thatfacility must replicate its radiation with both CSB and SBO antennas in a complex scenario that is large w.r.t. thewavelength. A new time domain method will be introduced to address this topic for dynamically disturbedenvironments. Separating its frequency modulated (FM) and amplitude modulated (AM) content, the indicatedbearing is calculated subsequently by determining the corresponding phase difference. Within the researchproject WERAN, an UAS-based (here: octocopter) platform with dedicated antennas, receivers and adaptedsignal processing was developed. Using this device, it is now possible to measure separately small phase errorson the 30Hz FM and AM signal components. According to the prediction, bearing errors due to existing windfarms are now traceable at specific positions in the airspace. Hence, the numerical results can be validated by insitu measurements of real DVOR signals-in-space in the environment of real WTs. The presentation will introducethe numerical method and the measurement platform and give an overview on the validation cases