Species

The KERNO classifier identifies these three: NBHF = Porpoise 'Other cet' = Dolphin Sonar = boat sonar but does not have a species class for these 2: Chance trains arising in noise WUTS = weak unknown train sources

Cetacean trains Sound amplitude rises and falls with the beam sweep - neat envelopes. click rate changes show varying trends. often fragmentary trains nearby. usually some multipath replicates of loud clicks. NBHF click clusters have small frequency spread Dolphin click clusters often show a wide frequency spread Chance trains - arise by chance from different sources many similar clicks in the background click rate trend erratic, or rising click amplitude envelope ragged Boat sonar trains Often very long clicks >30 cycles, but may be short 1 or 2, rarely up to 5, different intervals that repeat over minutes, no trend constant click frequency sometimes with harmonics often large multipath clusters a second frequency may be logged e.g. 50 & 200kHz

NBHF trains Click frequency in range 110 - 155kHz Multipath clusters and trains don't go outside this range. Multipath clusters show a small range of frequencies. Relatively long clicks - loud clicks are rarely < 7 cycles Bandwidth of clicks is low. 'other cetacean' trains Click frequency in range 30 - 160kHz Multipath clusters show a wide range of frequencies Relatively short clicks - loud clicks are often <6 cycles Long multipath click clusters Loud - trains with many clicks reaching the max value of 255 are common. Bandwidth of clicks is high.