SUBSIM Radio Room Forums - View Single Post - SCXIIC:How to correct the errors of sonar classification?

Captain Nemo · 02-08-08, 05:57 AM

Quote:

Originally Posted by sonar732

Quote:

Originally Posted by Stanny

I always assign trackers in broadband only.I use narrowband for classification purposes.I think,that if contact is invisible in broadband,there will be lots of problems tracking it in narrowband.For example,you may not be able to distinguish the bearing ambiguity or loose the contact while trying to do so.I prefer changing course from time to time,in order to scan different fields with towed array in broadband.I noticed,that course changes of ownship "prevent" weak contacts from escaping.

If you assign a tracker on a faint 50 hz tonal in NB, you'll have a better chance of detecting it earlier and a first shot probability on the platform. Think of it this way...you are looking at BB. Nothing is showing up in your STA waterfall, but you have a very faint line in ITA if you are lucky. There isn't a good enough SNR rating, so BB won't allow a tracker to be placed. However, if you go to NB, change your frequency to 100hz and place a tracker on the 50hz, you not only know that it's more than likely a sub, but also after a few speed, depth, and course changes, have a decent TMA reading when all you'd find out in BB is..."I know something is out there...don't know how far, but I know it's there"

Sonar732 has hit the nail on the head. I believe the SCX mod made detecting subs that are a long way off or are very stealthy much harder to detect in broadband. However, using the techniques described in narrowband you will detect subs much earlier and sometimes long before they appear in broadband. Since having an LCD monitor though, I have found it harder to use narrowband in this way which is a pity, my old CRT monitor was much better at showing faint tonals in narrowband.

Nemo