Atmospheric Acoustic Interferometer Tomography of Temperature and Winds

A technique is described for multiple-path propagation time measurements in the surface layer of the atmosphere. This is based on solving simple bi-directional ray tracing equations on successively higher penetrating paths using propagation times for a short acoustic pulse. The scattering process from turbulence is shown to be capable of providing signals from which phase comparisons can be made and time-of-flight deduced. Simulations demonstrate that the method has potential for deriving continuous temperature and wind profiles. In practice a multiple-beam interferometer can be used at each end of the path. Such an instrument has been designed and first results will be given, together with future planned enhancements.