LAUSR

Abstract The subject matter of the paper is concerned with improvement in the methods of measuring, processing and analyzing the infrasound noise caused by working wind turbines. The article presents results of measurements and analyses of infrasound signals emitted by work of a wind turbine with 2 MW nominal power, during its normal operation. Infrasounds were recorded at the same time in three independent and identical, in terms of the applied devices, measurement tracks. For the measurements of infrasound signals a dedicated measurement system was used. The measurements were made at variable weather conditions and for different distances between the measurement points and the turbine being examined. In the results part of the paper the following are subsequently presented: the time courses of the recorded infrasound signals, and then courses of the periodograms designated for them in frequencies and the spectrograms calculated for time-frequency data. Special attention was paid to the analysis of the possible application of time-frequency ridge transformation, the application of which enables effective extraction of energy-wise dominant instantaneous frequencies. In the summary, an analysis was made of the results obtained by means of frequency, time-frequency and time-frequency ridge analysis methods.