1. Species

2. 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

3. 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

4. NBHF trains
Click frequency in range kHz
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 kHz
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.