The fact, remains however, that the most modern diesel boats are virtually undetectable.
unless you are using active sonar, which the surface ships would routinely do if they are under attack... they are generally loathe to use it (i think) because it reveals their position, but once the first ship becomes a "flaming datum", skippers are going to start pinging and make it very uncomfortable for any subs in the vicinity.
Subs with passive sonars can hear an active sonar much further than vice versa. Think about homing countermeasures! (I modelled an active sonar system for my PhD dissertation, and I used to model submarine sonar systems for the Navy.)
Harry Erwin
"For a number to make sense in the game, someone has to calibrate it and program code. There are too many significant numbers that behave non-linearly to expect that. It's just a game. Enjoy it." herwin@btinternet.com
unless you are using active sonar, which the surface ships would routinely do if they are under attack... they are generally loathe to use it (i think) because it reveals their position, but once the first ship becomes a "flaming datum", skippers are going to start pinging and make it very uncomfortable for any subs in the vicinity.
Isn't thinck coat of rubber (and other "hush hush stuff") on submarine's hull supposed to negate this to quite a big extend (IIRC Russian submarines had 10-20 centimetes of it = 10-15 inches)?
Leo "Apollo11"
Well, it helps reduce signature, but certainly doesn't eliminate it... the flexible coating helps reduce the noise signature when moving through the water to make the boats more silent.
i will mention that there is technology available that allows one to passively detect silent objects in the water by use of their "acoustic shadow"... the noisier the underwater environment, the batter it works (supposedly)... however, i don't know if it is in service yet.
We use sound shadowing in our robot work.
Harry Erwin
"For a number to make sense in the game, someone has to calibrate it and program code. There are too many significant numbers that behave non-linearly to expect that. It's just a game. Enjoy it." herwin@btinternet.com
...but as the loss of the F117 over the Balkans proved, the use of different frequencies can defeat stealth measures.
Just a quick sidenote... the F-117 was, apparently, shot down using SA-3 with TV guidance (it was local ex-Yugoslav modification - I spend 12 months of my life with those 20 years ago)... the radar was not used at all (supposedly)...
...but as the loss of the F117 over the Balkans proved, the use of different frequencies can defeat stealth measures.
Just a quick sidenote... the F-117 was, apparently, shot down using SA-3 with TV guidance (it was local ex-Yugoslav modification - I spend 12 months of my life with those 20 years ago)... the radar was not used at all (supposedly)...
Leo "Apollo11"
I read an interview with the guy behind the shoot down recently. He said it had been noticed that the F-117A "appeared" on radar occasionally when subjected to a different wavelength. They set up on a known ingress route with altered equipment that emitted the different wavelength and waited... I think this had as much to do with this plane retiring as "budgetary" reasons...
...but as the loss of the F117 over the Balkans proved, the use of different frequencies can defeat stealth measures.
Just a quick sidenote... the F-117 was, apparently, shot down using SA-3 with TV guidance (it was local ex-Yugoslav modification - I spend 12 months of my life with those 20 years ago)... the radar was not used at all (supposedly)...
I read an interview with the guy behind the shoot down recently. He said it had been noticed that the F-117A "appeared" on radar occasionally when subjected to a different wavelength. They set up on a known ingress route with altered equipment that emitted the different wavelength and waited... I think this had as much to do with this plane retiring as "budgetary" reasons...
Nothing is completely radar invisible (i.e. stealthy)... I remember that even whan I was in the army (i.e. 20 years ago) the SA-3 battery did receive the training data from Russia (this was some kind of data tape cartridge) with F-117 radar signature...
What ultimately did shot down F-117A was "human factor" - the routes for USA planes were always the same (cardinal mistake! [X(]) and TV guided SA-3 (instead of radar to tract target TV, as passive source) was used by simply sitting below standard route...
