Acoustic Tomographic Monitoring of the Atmospheric Surface Layer

Abstract

Acoustic tomography is proposed as a method for monitoring near-surface atmospheric temperature and wind velocity fields. Basic issues relating to the feasibility and implementation of atmospheric tomography are discussed. Among these issues are the causes of fluctuations in acoustic signals propagated through the atmosphere, appropriate spatial dimensions of an array, signal detection and processing techniques, mathematical inverse techniques and their numerical implementation, and whether or not tomography m provide measures of dynamical variables of interest to atmospheric scientists. Surface-layer, horizontal-slice tomography was implemented experimentally, with an array of three sources and seven receivers distributed over a region approximately 200 m square. Travel-time fluctuations at the receivers were used to reconstruct the temperature and wind fields with about 50-m resolution in the horizontal plane.