Error Analysis for Micrometeorological Measurements Using Bidirectional Sound Probe with Long Baseline in Wind Fields

Abstract

We estimated the measurement errors caused by the errors in time of flight (TOF) and length of the baseline, in meteorological measurement using bidirectional sound probes with a long baseline. In addition, we simulated the measurement in three types of spatial wind distribution, using simple ray tracing. TOFs and the length of the sound ray were calculated for the three wind distributions. The calculated values of air temperature and wind velocity component derived from the TOFs and the length of the ray, were compared with their line-averaged values along the baseline. The results show good agreement. The errors were approximately -0.7°C for the air temperature and approximately -0.01 m/s for the wind component even in wind fields where a 20 m/s wind exists on the baseline. This indicated that the bidirectional-sound probe with a long baseline could satisfactorily carry out micrometeorological measurement in wind fields using conventional calculations.