03/08/2012 — admin
KILO MOANA’s acoustic signature was comparable to previous acoustical data with one noted exception. The levels in the EM 122 sonar operational frequency of 12 kHz were similar to historic data. A new problem was discovered that was associated with engine and switching room air handler cooling systems. This problem created 4,000 Hz harmonics from the fundamental up through 80 kHz (the limit of onboard instrumentation). An additional problem was noted with numerous elements of the EM 122 sonar array that is believed to be associated with electronic background noise.