1. Choice of Filters

2. Filters
This is CPOD.exe v2.050: Clicks shown are those that: pass all the filters and are within any TIME SELECTION that is set.
very useful!
train quality class
species from KERNO
species from KERNO
species from encounter classifier
trains
clicks
marked clicks / clicks with waveforms (F-POD)

3. Click filters: an example: How to find VEMCO fish tags
Using the click filters (not the train filters):
Set a long minimum click duration - say 30 cycles
Set a frequency range corresponding to VEMCO fish tags - say minimum 69kHz, max 71kHz.
Set a minimum number of clicks per screen - say 4 clicks
Set the skip file to file 1 - this slot will normally show the CP1 or FP1 file.
Use, say, 10ms time display resolution and the Duration view (F11)
Use F1 to move from screen to screen
Use F4 to remove and restore the filter so you can validate the identification on each screen.
Satisfy yourself that the filter is working.
Go to the Export page to export minutes with VEMCO tags heard.

4. } } } } true positives false positives
Sensitivity v specificity – what is the right level? } }
doubtful quality
low quality
This is a ‘ROC curve’
= receiver operating characteristic
It’s different in different environments.
true positives }
moderate quality
Start with tough criteria and no detections.
As you make your detection criteria weaker you move along the red line
and you get more detections …
and more and more errors. }
high quality
false positives
Hi + Mod is the standard because Low Q trains are commonly generated by adverse conditions - noise

5. } } } } true positives false positives In a noisier place:
doubtful quality
true positives
low quality }
moderate quality }
high quality
false positives

6. Encounter classifiers
take information from a sequence of trains with no gap longer than n minutes.
this move to a higher level gives more information on the train source.
GENENC - a 'generalised encounter classifier' detects more dolphin trains, and usually reduces mis-identification of dolphins as NBHF species.
HEL1 - developed for porpoise detection in Baltic Sea data at the Hel Marine Station in Poland. It assumes there are no dolphins.

7. Encounter classifiers
this can be used to exclude VEMCO fish tags
Encounter classifiers need the CP3 or FP3 file to exist
run very quickly.

8. Standard filtering
KERNO or GENENC.
Hi + Mod Quality trains

9. the end
useDPM, Hi + Mod quality trains