ACOUSTIC TOMOGRAPHIC MONITORING OF THE ATMOSPHERIC SURFACE-LAYER

Acoustic tomography is proposed as a method for monitoring near-surfac e atmospheric temperature and wind velocity fields. Basic issues relat ing to the feasibility and implementation of atmospheric tomography ar e discussed. Among these issues are the causes of fluctuations in acou stic signals propagated through the atmosphere, appropriate spatial di mensions of an array, signal detection and processing techniques, math ematical inverse techniques and their numerical implementation, and wh ether or not tomography can provide measures of dynamical variables of interest to atmospheric scientists. Surface-layer, horizontal-slice t omography was implemented experimentally, with an array of three sourc es and seven receivers distributed over a region approximately 200 m s quare. Travel-time fluctuations at the receivers were used to reconstr uct the temperature and wind fields with about 50-m resolution in the horizontal plane.