The effect of averaging time on the statistical properties of sensor records

Abstract

The paper presents the results of an analysis of the sensitivity to time smoothing of the concentration records from the Thorney Island trials. It is shown that averaging times greater than about one second can have significant effects on the concentration records. The observed peak is then attenuated to an extent which is greater than the uncertainty associated with the instrumentation. The loss of information is dependent on the chosen averaging time and needs to be considered in any comparison of the measurements with the predictions of models. The paper also reports on a preliminary analysis of the turbulence records both inside and outside the cloud. It was not possible from the results of this analysis to delineate any influence of the dense gas on the turbulent structure within the cloud.