Dear colleagues,

My co-authors and I are pleased to announce the publication of the following article in JASA:

Pereira, A., Harris, D., Tyack, P., and Matias, L. (2020). "On the use of the Lloyd's Mirror effect to infer the depth of vocalizing fin whales," The Journal of the Acoustical Society of America 148, 3086.


ABSTRACT
The interference between the direct path and the sea surface reflection of a signal as measured by a receiver is called Lloyd's Mirror effect (LME). It results in a frequency-dependent interference pattern that can be observed in a spectrogram. LME depends on the receiver depth, signal source depth, signal frequency, and slant range between source and receiver. Knowing three of these parameters a priori, LME can be used to estimate the third parameter, such as source depth. Here, the work in Pereira et al. (2016) was expanded to estimate the depth of a vocalizing fin whale recorded by an ocean-bottom seismometer (OBS). In Pereira et al. (2016), the depth of a vocalizing fin whale was inferred by manually comparing spectrograms of LME transmission loss models with observed LME. This study developed an automated procedure to perform the same task using the LME interference pattern observed in the spectrograms of the hydrophone and the vertical channel of the OBS. The results show that the joint use of the two channels was the best approach to estimate a source depth using LME. LME provides a non-intrusive approach for estimating the depth at which a fin whale was vocalizing.


Please contact me for the full text and supplementary material and if you have any questions. You can also find the article in the following link:
https://doi.org/10.1121/10.0002426



Best wishes,
Andreia Pereira