Pondering over the possibilities of synchronising Hydromoths to avoid clock drift, and in turn localising audio signals, particularly in a marine environment.
For context, the clock drift across audiomoths confounds the localisation problem. The added feature of a GPS sync within each unit would be helpful to bring the clock drifts down < 2us but in an underwater environment, this would not be possible without a surface buoy.
Emitting artificial sounds from a nearby speaker to time-sync instruments could be a possibility but that requires regular syncs with devices being equally spaced apart.
Has anyone tried any other techniques to time-sync and/or localise sounds using a Hydromoth underwater?