Results from the Elba HF-2003 experiment

Abstract

In October of 2003, a high-frequency propagation and acoustic communications experiment was conducted off the Italian island of Elba. The experiment followed closely a previous experiment off Kauai (Hawaii Islands) [1]. In particular, a 5 km propagation path along the 100-m isobath was selected. Relative to the Kauai Experiment, the Elba test was significant both in terms of what was similar and what was different. The experiment geometry was identical and a similar mixed layer structure was expected. However, since NURC has worked extensively in this area in past tests we were able to confidently select two sites, one with a very soft bottom and one with a very hard bottom. The comparison between measurements at the two sites in Elba and in Kauai is very illuminating in terms of the propagation conditions and the performance of the acoustic communications scheme. A final significant change was the inclusion of multiple input/multiple output (i.e. using source/receive arrays) communications schemes. We summarize preliminary results from this experiment.

High-Frequency Geoacoustic Inversion of Ambient Noise Data Using Short Arrays

“…The next section gives a short description of the beamforming issues that, in some cases, hinders obtaining the ambient noise inversion. Finally, data from the recent ElbaEx experiment [3] is used to demonstrate the inversion technique.…”