What is this on the Towed Array?

swampy · 02-10-13, 07:12 PM

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

Kapitan · 02-17-13, 02:56 PM

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

Takeda Shingen · 02-18-13, 07:43 PM

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.

swampy · 02-19-13, 11:49 AM

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

OptimusX · 03-09-13, 08:51 PM

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?

02-17-13, 02:56 PM	#2
Kapitan Sub Test Pilot Join Date: Mar 2005 Location: UK + Canada Posts: 7,130 Downloads: 77 Uploads: 7	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 __________________ DONT FORGET if you like a post to nominate it by using the blue diamond Find out about Museum Ships here: https://www.museumships.us/ Flickr for all my pictures: https://www.flickr.com/photos/131313936@N03/ Navy general board articles: https://www.navygeneralboard.com/author/aegis/

02-18-13, 07:43 PM	#3
Takeda Shingen Navy Seal Join Date: Mar 2000 Posts: 8,643 Downloads: 19 Uploads: 0	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.

02-19-13, 11:49 AM	#4
swampy Torpedoman Join Date: Mar 2008 Posts: 118 Downloads: 188 Uploads: 0	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

03-09-13, 08:51 PM	#5
OptimusX Seaman Join Date: Mar 2004 Posts: 31 Downloads: 27 Uploads: 0	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?