TOMOGRAPHY DETAILS
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Five 200-Hz transceiver moorings (T1 to T5), each equipped
with a sound source and a 5-element vertical hydrophone array
were deployed about 1100 m depth over a 1000 km scale
domain centered at 33° N, 149° E; the five-mooring
array produced 10 horizontal connecting paths.
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Each mooring is equipped with a surface buoy for
Global Positioning System timekeeping and real-time data
telemetry, so that the inverse analyses of
the acoustic travel time can be done in parallel with
sound transmission and reception.
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All of the transceivers were placed on TOPEX/POSEIDON
(T/P) satellite altimeter ground tracks. Paths T2-T5 and
T3-T4 were put along the descending T/P ground tracks p238 and
p136, respectively, to simplify the comparison of the
acoustic tomographic data the T/P altimeter data.
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The sound transmissions occurred every 3 hours in August and
every 6 hours in July and September within a 2-hour interval relaying
around the five moorings.
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The mooring motion was tracked using local long baseline acoustic
navigation nets.
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Transceiver position uncertainties were estimated to be approximately
2 meters, corresponding to a few milliseconds uncertainty of
acoustic travel time.
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