Influence of the averaging time on the quality of reconstruction of small-scale wind turbulence characteristics in acoustic sounding

Abstract

Influence of the averaging period on the quality of reconstruction of the wind velocity structure functions and characteristics from the data of minisodar measurements is investigated. Values of the structure functions and characteristics averaged over 10, 20, 25, 30, and 60-min periods are presented. Results of their calculations using an original algorithm demonstrate that the structure characteristic decreases with increasing averaging time. Thus, for the 10-min averaging period, the velocity structure characteristic calculated for one series of minisodar measurements was 0.00376 m4/3/s2 for sounding altitude of 100 m; it significantly decreased (by 37%) for the 20-min averaging period, and decreased by less than 5% for the 25-min averaging period. This allows us to recommend the 20-min averaging period as optimal one for investigation of the dynamics of smallscale wind turbulence using acoustic sounding.