Healy - Knudsen 320 B/R
The Knudsen 320B/R has two transceivers and is capable of operating as a subbottom profiler (CW at 3.5 KHz or frequency modulated chirp from 2kHz to 6 kHz) and a conventional single beam echo sounder at 12 KHz. The transceiver and computer are installed in IC/Gryo with the display, keyboard and mouse remoted to the Science Watch Standers Workstation in the Computer Lab. It is possible to run both modes simultaneously. Heave correction from the POS/MV is applied. Position data comes directly from a GPS receiver. During normal operation on the Healy, the 12 KHz mode is not used as it interferes with operation of the swath mapping (multibeam) system. The subbottom transducer array consists of sixteen Ocean Data Equipment Corp. TR-109 elements configured in a four by four array wired in a series-parallel arrangement and mounted in a transducer well inside the ship. Like the multibeam array, the transducers are protected from the sea ice by a thick polyurethane ("SeaBeam Orange") windows. The 12 kHz transducer is a Ocean Data Equipment Corp. TC-1234. By prior arrangement, this transducer may also be used for interrogating acoustic transponders and releases with an appropriate user-supplied deck unit. Knudsen data is not corrected for sound speed, it is collected using a uniform sound speed of 1,500 meters per second. Knudsen data is heave compensated with input from the POS/MV. Data files are routinely logged in KEA, KEB and SEG-Y formats. Click here for a review of Sub-Bottom profiler processing.