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Post by privatepaddy on Jan 1, 2013 13:55:28 GMT
USS Blandy DD943 1968 Vietnam lays down smoke
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Post by srracing on Jan 1, 2013 21:35:22 GMT
Neither RADAR nor a guy with binoculars can look past the horizon! OTH Radar has been in use since the 50's and on US carriers since the 60's. |
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Post by OziRiS on May 19, 2013 21:10:28 GMT
Neither RADAR nor a guy with binoculars can look past the horizon! OTH Radar has been in use since the 50's and on US carriers since the 60's. I found that statement a little strange too. I've worked on an RDAF semi-mobile radar (could be moved in a relatively short amount of time, but wasn't fixed to a vehicle) that had a range of 155 miles. The "horizon" is only about 3 miles out if you're standing at sea level. |
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Post by privatepaddy on May 27, 2013 12:19:41 GMT
OTH Radar has been in use since the 50's and on US carriers since the 60's. I found that statement a little strange too. I've worked on an RDAF semi-mobile radar (could be moved in a relatively short amount of time, but wasn't fixed to a vehicle) that had a range of 155 miles. The "horizon" is only about 3 miles out if you're standing at sea level. I believe C64 is a communications specialist from what he writes, I am not sure he knew much about ships of the era. Its been too many years and too many beers since I served aboard a ship. I believe it was refitted with a M-22 fire control system and D-01/2 EWR? it was from the Netherlands. At the time its performance and its specifications were privy only to the operators, WR ratings and the Russians ;D |
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Post by c64 on May 7, 2014 12:39:39 GMT
There are 3 Methods for OTH Radar:
OTH-B (Over-The-Horizon – Backscatter) and OTH-SW (Over-The-Horizon – Surface Wave) are the classic methods. In both cases, you send out a massive but short impulse on a very low frequency. Just like short-wave and long-wave radio signals, the pulse energy will either crawl over the earth's surface (OTH-SW) using very low frequencies or bounce off the ionosphere (OTH-B) using long but not that long waves.
The problem is that anything smaller than about 1/4 of the wavelength of the OTH is invisible. OTH-SW can see very large ships but no aircrafts. Since the propagation of the signal is highly predictable, you get a good range and good bearings. OTH-B isn't very predictable since it bounces off the ionosphere at an altitude which can't predicted that accurately. While you still get a good bearing, you can't tell the range accurately. Also there are many "blind" zones beneath the bounces in the ionosphere you need to cover by sweeping the elevation of the antennae.
The problem of classic OTH Radar is that the signal reaches a lot further than the maximum range where you can detect return signals. This allows your enemy to pinpoint you highly accurate while still undetected.
Modern OTH using computers can use complex signal patterns to extend the range without the need of much power. This also prevents accurate pinpointing the origin of the signal by the enemy so you only reveal your bearing to the enemy but not your range.
But the modern OTH Method of choice are satellite radio links. Just put up several airborne radars somewhere which have a tremendous range simply by altitude so they can stay far away out of the reach of the enemy. And there is absolutely no clue which vessels anywhere in the world receive the radio link and can make use of. So you don't need to emit anything, just receive the radio data link to see everything in your area (including yourself). And if the enemy shoots a RADAR homing missile, the targeted airborne RADAR just goes offline and can use the data links of other airborne RADARs to evade the missile.
Using classic OTH RADAR reveals your own position long before you detect the enemy. Using conventional RADAR is better but breaks even with a good pair of binoculars. So the method of choice nowadays is using no RADAR at all except airborne radar which can see everything but reveals nothing to the enemy.
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Post by paulsee on May 22, 2014 12:58:44 GMT
The Light works wrote :
"When you find a naval engagement circa 1939-1945 that fits your hypothetical criteria please provide a link as I would be interested in reading such an account. As said elsewhere I am not a naval historian but growing up naval history was a passion. So it is possible, but highly improbable in my opinion, that a fleet commander would make voluminous amounts of smoke as a subterfuge and give his position away to not only the opposing fleet but any lurking enemy submarine, other surface units or aircraft patrols."
- Unsure if this will qualify, but the destroyers of the Battle of Leyte Gulf used smoke to conceal the taffy carriers positions and ultimately make the Japanese retreat because the IJN commander Kurita thought they were facing a whole carrier task force.
- Not exactly smoke and naval, but Rommel used the dust cloud of the vehicles to make it appear that the DAK had more vehicles than
was really there.
For the modern naval use, not sure how useful they could be in open water. The use may be more Littoral where the landing forces may need smoke to cover the Amphibious landings. Not exactly naval, but more Marine I think.
Hope this helps
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Post by the light works on May 22, 2014 16:18:37 GMT
The Light works wrote : "When you find a naval engagement circa 1939-1945 that fits your hypothetical criteria please provide a link as I would be interested in reading such an account. As said elsewhere I am not a naval historian but growing up naval history was a passion. So it is possible, but highly improbable in my opinion, that a fleet commander would make voluminous amounts of smoke as a subterfuge and give his position away to not only the opposing fleet but any lurking enemy submarine, other surface units or aircraft patrols." - Unsure if this will qualify, but the destroyers of the Battle of Leyte Gulf used smoke to conceal the taffy carriers positions and ultimately make the Japanese retreat because the IJN commander Kurita thought they were facing a whole carrier task force. - Not exactly smoke and naval, but Rommel used the dust cloud of the vehicles to make it appear that the DAK had more vehicles than was really there. For the modern naval use, not sure how useful they could be in open water. The use may be more Littoral where the landing forces may need smoke to cover the Amphibious landings. Not exactly naval, but more Marine I think. Hope this helps actually, someone else must have written that, unless I am unknowingly suffering from MPD. but it is a good point that smoke has been used to cause uncertainty about your forces. |
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Post by Cybermortis on May 22, 2014 21:47:55 GMT
Smoke is effective against visual, and to some degree laser, targeting systems. But useless against radar targeting systems.
Basically two warships facing off would not bother with smoke, since it isn't going to have any effect on their opponents ability to detect and target them - and these days warship engagements are unlikely to take place within visual range anyway.
However, this is 'blue water' thinking where you are a long way from land. Closer to shore or in narrower seas and straights smoke screens are still effective.
Even fairly light shore batteries could make a mess of a modern warship in short order, but they are unlikely to be using radar targeting systems - if only because turning such a system on marks it as a target for every aircraft in the area. So smoke screens can mess up shore based battery fire, making it less accurate and of course helps cover landing craft if any are being deployed.
Closer into shore you also run into the risk of facing not warships, but gunships - or even just a rubber dingy with a guy standing at the bow with an RPG. These are small fast boats, can be hard to see on radar since they are so low in the water and because they are operating close to shore may be able to dart out from a sheltered location to perform hit and run attacks against larger ships. While it is unlikely that an RPG could sink a frigate or destroyer, it could still cause enough damage to force a ship to head back to port for expensive repairs. So again, smoke screens work well because such vessels lack systems that could see through the smoke to aid in targeting.
The irony is that older WW2 era ships would probably find smoke-screens less useful than modern ship designs would today. The reason being that the older ships carried a not inconsiderable amount of armour, which made them much more capable of withstanding hits that would cripple a modern ship.
Ships, like all military vehicles, have to strike a balance between protection, mobility/speed and firepower. Post-war designers followed the (not entirely unreasonable) logic that armour was rather pointless if your opponent hit you with a nuke. So instead they removed the armour to concentrate on firepower and speed. Experience in the Falklands war, and incidents in the Gulf during the 1980's, challenged this idea and ships today have some armour, even if it is only protecting the more vital sections rather than the entire hull. But they are still largely designed to be fast and avoid being shot at rather than being able to withstand hits.
The speed issue is also a question of what modern warships are designed and intended to do. And ironically that isn't, usually, to actually fight other warships. More often ships are used as a deterrent, which requires being able to deploy to trouble areas fast, or for emergency aid. Which again requires a fast deployment.
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Post by the light works on May 23, 2014 0:07:28 GMT
Smoke is effective against visual, and to some degree laser, targeting systems. But useless against radar targeting systems. Basically two warships facing off would not bother with smoke, since it isn't going to have any effect on their opponents ability to detect and target them - and these days warship engagements are unlikely to take place within visual range anyway. However, this is 'blue water' thinking where you are a long way from land. Closer to shore or in narrower seas and straights smoke screens are still effective. Even fairly light shore batteries could make a mess of a modern warship in short order, but they are unlikely to be using radar targeting systems - if only because turning such a system on marks it as a target for every aircraft in the area. So smoke screens can mess up shore based battery fire, making it less accurate and of course helps cover landing craft if any are being deployed. Closer into shore you also run into the risk of facing not warships, but gunships - or even just a rubber dingy with a guy standing at the bow with an RPG. These are small fast boats, can be hard to see on radar since they are so low in the water and because they are operating close to shore may be able to dart out from a sheltered location to perform hit and run attacks against larger ships. While it is unlikely that an RPG could sink a frigate or destroyer, it could still cause enough damage to force a ship to head back to port for expensive repairs. So again, smoke screens work well because such vessels lack systems that could see through the smoke to aid in targeting. The irony is that older WW2 era ships would probably find smoke-screens less useful than modern ship designs would today. The reason being that the older ships carried a not inconsiderable amount of armour, which made them much more capable of withstanding hits that would cripple a modern ship. Ships, like all military vehicles, have to strike a balance between protection, mobility/speed and firepower. Post-war designers followed the (not entirely unreasonable) logic that armour was rather pointless if your opponent hit you with a nuke. So instead they removed the armour to concentrate on firepower and speed. Experience in the Falklands war, and incidents in the Gulf during the 1980's, challenged this idea and ships today have some armour, even if it is only protecting the more vital sections rather than the entire hull. But they are still largely designed to be fast and avoid being shot at rather than being able to withstand hits. The speed issue is also a question of what modern warships are designed and intended to do. And ironically that isn't, usually, to actually fight other warships. More often ships are used as a deterrent, which requires being able to deploy to trouble areas fast, or for emergency aid. Which again requires a fast deployment. it might be more to the point to say that naval armor doctrine is based on withstanding hits from the smaller weapons, like machine guns and light RPGs, that they can expect to face in skirmishes with pirates and such. |
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Post by paulsee on May 23, 2014 13:40:50 GMT
The lightworks wrote: "actually, someone else must have written that, unless I am unknowingly suffering from MPD.
My apologies, I am in error, it was written by someone else.
Concerning blue water application of smoke, I agree that old style smoke screens generated by ships would seem useless.
However, I think if a combined Radar decoy that emits an IR sensor smoke screen might be useful. Assuming a swarm of Anti ship missiles (ASM) are on the way, deploying Radar decoys that emit an ir blocking/bloom smoke screen might be effective. The objective might be to induce the ASMs to detonate or decoy them away from the fleet. The radar decoys would entice the radar of the missiles, the ir smoke would block or entice any ir sensors of the missiles.
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Post by Cybermortis on May 23, 2014 14:05:40 GMT
Note that anything that blocks an enemies IR sensors is going to block yours. Same with radar decoys - they can mess your targeting systems up as much as an enemies. Which when you are talking about automatic point defence guns may not be the best of ideas.
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Post by the light works on May 23, 2014 14:17:54 GMT
The lightworks wrote: "actually, someone else must have written that, unless I am unknowingly suffering from MPD. My apologies, I am in error, it was written by someone else. Concerning blue water application of smoke, I agree that old style smoke screens generated by ships would seem useless. However, I think if a combined Radar decoy that emits an IR sensor smoke screen might be useful. Assuming a swarm of Anti ship missiles (ASM) are on the way, deploying Radar decoys that emit an ir blocking/bloom smoke screen might be effective. The objective might be to induce the ASMs to detonate or decoy them away from the fleet. The radar decoys would entice the radar of the missiles, the ir smoke would block or entice any ir sensors of the missiles. just didn't want to claim credit for someone else's intelligent remark. |
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Post by the light works on May 23, 2014 14:19:48 GMT
Note that anything that blocks an enemies IR sensors is going to block yours. Same with radar decoys - they can mess your targeting systems up as much as an enemies. Which when you are talking about automatic point defence guns may not be the best of ideas. true, it would be more useful if you were shelling a distant target. and didn't want to give their return fire a clear target. (your FO would be handling fine aim at that point) |
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