What is this on the Towed Array?
 

The FFG towed array shows this. 39 is a tagged trawler. But what does the 9 stand for? How can there be a contact at such a low frequency?

Using Lwami 3.11

possibly a glitch but trawlers normally have 4 blades high revolutions and only average speed so they tend to be noisey it could also be a mirror IE its not actually there if you make a turn then you may clear the mirror the FFG towed array is very sensitive but 39Hz is a bit low

If you're using the autocrew for the station they will often find contacts before you should be able to hear or see them. It's why I like to man that station myself. What you are seeing there is a very distant contact.

No Im not using autocrew. Yes your right the contact is very far away, so as far as I understand the number 39 is at 50-60 Hz and as I move closer, I will detect higher frequencies to the right in the first row and then at the 2 other rows.

So mabye the 9 is a high frequencie from another contact on the beam above?

I will do some more testing

I think it may be possible for frequencies of a weak signal to become distorted over very long distances. I'm thinking along the lines of Doppler effect, maybe?