An Electronic Computing Wind Vane for Turbulence Studies

Abstract

This paper describes an electronic wind vane which has been designed for meteorological support during atmospheric diffusion studies. The wind vane avoids the use of any sliding contacts for giving an analogue record of the wind direction in the atmosphere, and computes the standard deviation of horizontal wind direction fluctuations by measuring the accumulated value of the displacements of the wind vane and the number of reversals of wind direction during a predetermined interval. The sensor for wind direction and reversal measurements is a set of two mutually coupled rf coils separated by a continuously varying slot aluminum disc coupled to the shaft of the wind vane. The displacements of the wind vane are measured with the help of a photocell. The instrument has been operated at one of the meteorological stations at Trombay for the study of turbulence patterns on the local hilly terrain. Results of these studies have been used for an estimate of the diffusion climatology at Trombay.