Marine Physical Laboratory, Scripps Institution of Oceanography, La Jolla, California 92093-0238, USA.
J Acoust Soc Am. 2011 Dec;130(6):3633-41. doi: 10.1121/1.3654026.
The passive fathometer algorithm was applied to data from two drifting array experiments in the Mediterranean, Boundary 2003 and 2004. The passive fathometer response was computed with correlation times from 0.34 to 90 s and, for correlation times less than a few seconds, the observed signal-to-noise ratio (SNR) agrees with a 1D model of SNR of the passive fathometer response in an ideal waveguide. In the 2004 experiment, the fathometer response showed the array depth varied periodically with an amplitude of 1 m and a period of 7 s consistent with wave driven motion of the array. This introduced a destructive interference, which prevents the SNR growing with increasing correlation time. A peak-tracking algorithm applied to the fathometer response of experimental data was used to remove this motion allowing the coherent passive fathometer response to be averaged over several minutes without destructive interference. Multirate adaptive beamforming, using 90 s correlation time to form adaptive steer vectors which were applied to 0.34 s data snapshots, increases the SNR of the passive fathometer response.
被动测深仪算法应用于地中海边界 2003 年和 2004 年的两次漂流数组实验的数据中。使用 0.34 到 90 秒的相关时间计算被动测深仪的响应，对于小于几秒钟的相关时间，观察到的信噪比（SNR）与理想波导中被动测深仪响应的 SNR 的 1D 模型一致。在 2004 年的实验中，测深仪的响应显示数组深度周期性地变化，幅度为 1 米，周期为 7 秒，与数组的波驱动运动一致。这引入了破坏性干扰，阻止 SNR 随相关时间的增加而增加。应用于实验数据的测深仪响应的峰值跟踪算法用于去除这种运动，从而允许相干被动测深仪响应在没有破坏性干扰的情况下平均几分钟。使用 90 秒相关时间形成自适应导向矢量的多速率自适应波束形成，并将其应用于 0.34 秒的数据快照，提高了被动测深仪响应的 SNR。
