Question for you radar observers..

nolatom · #1 (**permalink**) 01-04-2010

I've been looking at some of the new Navy ship "stealth" hull designs, like the soon to be USS Independence, a fast littoral ship.

They all have the angled plating and surfaces to make them a poor to zero radar target.

So how does this work when you're scanning your own radar at night or in the fog and one of them is in range? You see no target, I assume? Anyone been there? Is there a way a stealth ship who wants to be radar-visible can do it?

Just curious. With good radar and AIS, larger vessels are easy to detect. Without both (assume Navy doesn't broadcast AIS, or do they?), are you back in the foghorn days?

Maine Sail · #2 (**permalink**) 01-04-2010

Quote:

Originally Posted by nolatom

I've been looking at some of the new Navy ship "stealth" hull designs, like the soon to be USS Independence, a fast littoral ship.

They all have the angled plating and surfaces to make them a poor to zero radar target.

So how does this work when you're scanning your own radar at night or in the fog and one of them is in range? You see no target, I assume? Anyone been there? Is there a way a stealth ship who wants to be radar-visible can do it?

Just curious. With good radar and AIS, larger vessels are easy to detect. Without both (assume Navy doesn't broadcast AIS, or do they?), are you back in the foghorn days?

I think the bigger concern are the thousands of boats out there that are poor radar targets and don't even know it, nor attempt to even invest in a radar reflector or active radar reflector.

puddinlegs · #3 (**permalink**) 01-04-2010

I'd assume that unless in a state of war, a ship of your description would have to operate locally under colregs like everyone else. I'd imagine that in the fog with a poor or non-existent radar sig, they'd be tooting away like the rest as well as more than likely being accompanied by the coast guard as is usually the case with warships in our area.

GeorgeB · #4 (**permalink**) 01-04-2010

I happened to be sailing out in the Gulf of the Farallones on Saturday of this year’s San Francisco Fleet Week. The Navy had sent a Littoral Combat Ship to participate. It was forming up with a USCG high endurance cutter and for fun, I fired up my 2KW Raymarine set. Very surprisingly, the Combat Ship lit up like a Christmas tree, giving a larger return than South Farallone! I can only surmise that the Combat ship has some sort of transponder that amplifies the return signal as its return signature made the cutter’s practically stealthy in comparison.

nolatom · #5 (**permalink**) 01-04-2010

That's kinda what I was wondering. Stealth is great, except when you want to be seen, which is most of the time when you're navigating sans war or war games.

klem · #6 (**permalink**) 01-04-2010

If you were to try to see one on radar, you would see what looked like scatter. Therefore, they have a radar transmitter that they switch on to provide an active radar target. With this, they will show up much better than other targets.

Making ships/planes stealth is really fascinating stuff. There is a lot more that goes into it than simply trying to deflect signals.

bobwebster · #7 (**permalink**) 01-05-2010

I generally would not rely on the "other guy" to avoid me, but I'm pretty sure a U.S. Navy ship is not going to accidentally run over a recreational sailboat. Lack of diligence is not a problem in the navy.

SVPrairieRose · #8 (**permalink**) 01-05-2010

Quote:

Originally Posted by bobwebster

I generally would not rely on the "other guy" to avoid me, but I'm pretty sure a U.S. Navy ship is not going to accidentally run over a recreational sailboat. Lack of diligence is not a problem in the navy.

Clearly you didn't hear about the US sub surfacing under the sailboat in the Straight of Georgia... Or the Japanese fishing boat.

motion300 · #9 (**permalink**) 01-05-2010

Quote:

Originally Posted by bobwebster

I generally would not rely on the "other guy" to avoid me, but I'm pretty sure a U.S. Navy ship is not going to accidentally run over a recreational sailboat. Lack of diligence is not a problem in the navy.

WELL one would think that but.......I was running south in the chesapeake bay in 07 on the start of mt trip south on the ICW near the patx river, close to the large LP loading dock there. My buddy who was standing watch called, hey come up here, I looked through the binos and there was a STORM comming at us maybe 1/2mile away It was a Navy cat boat probably 250' running mabe 40mph crossing my my port bow I thought well he will turn before he gets to close. WRONG at the speed I was running 8mph I could not get away from him as I tried. .When we were with in 200yards the navy boat made a very hard turn to stb at the same time we did the same damn it was to close for me and the resulting wave really ratteled us I could not see the captain as he was 4 stories above me Never heard a word from the radio and then that was gone What fun

firstlcscommissioner · #10 (**permalink**) 01-05-2010

GeorgeB, Your radar might have been lighting up a Littoral Combat Ship (assuming it could reach the East Coast), but your eyes were not seeing one. There has never been an LCS in the Pacific. USS Freedom (LCS 1) has never left the Atlantic, and soon to be USS Independence (LCS 2) has never left the Gulf of Mexico. Besides, the Lockheed Martin version (Freedom) was not intended to be a stealth design -- just fast.