Sensor

Homogeneous stereo hydrophone (MHP-140-140)

Stereo hydrophone MHP-140-140 has identical two hydrophones, which is most sensitive at 130kHz (-200.0dB re 1V/uPa). This is suitable for the area having only one species of odontocetes in a noisy environment

Heterogeneous stereo hydrophone (MHP-140-70)

Stereo hydrophone MHP-140-70 has two differnt hydrophones. The first one is most sensitive at 130kHz same as above.The second one is most sensitive at 70kHz(-200.2 dB re 1V/uPa). It is suitable to identify Phocoenidae species such as harbor porpoises and finless porpoises out of Delphinidae species using two band comparator.

Data stored

Sound pressure

Sound source direction can be pressure received at both hydrophones are stored every 0.5 ms (minimum setting). Copmarison of two band received level between primarily (130kHz) and slaver (70kHz) hydrophone provides an index of falimy (Phocoenidae/Delphinidae).
-Minimum detection threshold level: 130 dB p-p re 1uPa @ 100kHz
-Resolution 10 bits
-Dynamic range 130dB-157 dB p-p re 1uPa @ 100kHz
-Band pass filter 55kHz - 235 kHz
-Sampling interval 0.5ms, 1ms, 2ms

Sound source direction

Sound source direcetion of a phonating animal is calculated from the time arrival difference of a sound between two hydrophone. An independent high speed counter starts when a received level of a hydrophone over preset detection threshold level until the second trigger happnes at the other hydrophone.
-Resolution of the high speed counter: 271.265ns, 542.53ns, 1085.06ns
-Dynamnic range (10 bits): +/- 139us, +/-278us, +/-556us
(corresponding to sampling intervals 0.5 ms, 1ms and 2ms)

Start mode and lifetime

Timer mode

Delay timer to start (0-255hours)

Clock mode

Start at specific time and day

Intermittent mode

Interval recording (interval 1-255 minute>recording 1-255 minute, 1min step)

Recording time and batteries

For Normal type, it records up tp 30 hours. For Longlife type, it record up to 1 month. Battery capacity limits the lifetime, not the memory capacity. Storage: 42,500,000 data (1Gbit or 128MB flash memory).
-CR2 (commercial lithium battery) x 1 (Normal type)
-D cell x 2 for for long term use (Longlife type)

Interface to PC

Hardware

Interface box (MIF-200) and cable (MIFC-1) is used to communicate with A-tag

Software

Logger Tools ver.4.40 is the software for setup and loading data of A-tag by PC. For visualization and analysis, click here to download free source codes working on Igor Pro. You need to install Igor Pro (Wavemetrics). Note thid is not free

Size and shape

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