| Summary: | Progress Code: completed Statement: The Dates provided in temporal coverage are approximate only, and represent the beginning and end of the 2005 - 2012 Antarctic seasons. The latitudes and longitudes provided in spatial coverage are approximate only. The following information relates specifically to the Tangaroa.Sonobuoy.Log.xls file: National Instruments Card Gain is the amount of gain the sound card added to the signal. 1 gain means the input voltage range is from -5 to +5 volts 5 gain means the input voltage range is from -1 to +1 volts I think we ended up using a gain of 5 in most cases since even loud audio signals were typically between +/-1 V. Basically, these set the bounds/rails on what the sound card can read as part of an acoustic signal. If the signal is particularly intense and produces a higher voltage than +/-1 (in the case of a gain of 5) then the signal peaks or 'hits the rail' and is still recorded as a +/-1V signal (distorting the sound recorded). The voltage range of the audio signal is determined by a chain of things from the hydrophone sensitivity on the sonobuoy and how this is transmitted to the boat's receiver, and ultimately the sensitivity of the VHF receiver in converting the VHF signal back to an audio signal. Check the dataset for calibration files. The manual for the sound card can be found at the following website: http://www.ni.com/pdf/manuals/370503k.pdf 2. Unit for frequency should be Hz (hertz). 3. Depth is Meters 4. Yellow highlighted boxes are from sonobuoys that failed (i.e. they were deployed, but no or minimal useful audio signal was recorded from them) Taken from the 2008-2009 Progress Report: Field work: As described above, recovery attempts were made on 3 acoustic dataloggers that were deployed in 2007/8 along a line of longitude south of Tasmania (142 E) from just SW of Tasmania (44 S), to halfway between Tasmania and the Antarctic (54 S), to just off the Antarctic continental shelf (65 S). These instruments will be recovered during the 08/09 season. Unfortunately, ...
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