Airborne measurements characterising the impact of wind turbines on VHF radio channels
Résumé
The question how much wind turbines interfere with radio channels is one that has been increasingly
posed over the last decade. This coincides with the increasing number of wind turbines, both on-
shore and off-shore. To analyse how wind turbines effect VHF radio channels a series of
methodologies is employed by different research teams: Ground and airborne-based measurements,
mathematical models and simulations. In this talk, airborne measurements using an aeroplane will be
presented as a profound method: They provide a fundamental understanding about the effects of
wind turbines on the VHF radio signal in free space.
The talk discusses the airborne measurement platform for characterising VHF radio links. This
platform consists of two parts. One part is the VHF antenna system. The receiving antenna and the
impact of the aeroplane itself will be presented. The other part is about the receiver system. It is
based on a purpose-made software-defined radio (SDR). This SDR is optimised with respect to a huge
dynamic range as well as for amplitude linearity and absolute time accuracy.
Furthermore, the talk discusses the results of first measurement test flights. These test flights yield
information about the operational capability of the whole system. On this occasion, offshore
automatic identification system (AIS) signals measured. The analysis of the captured data provides
information about the field strength fluctuation and influences caused by wind turbines.