Radar, sonar and other modern military sensors

Wolverine · Oct 26, 2009

Re: How Do You Sink A Carrier?

Ambivalent said:
Wolverine, ICWI capability in SM-2 pre-dates any shipboard AESA. It dates to the 1980's when SPY-1 was state of the art and no other navy had even a passive electronically scanned radar, much less an AESA.
Again, you do not need agile beam steering or an AESA to achieve the early form of ICWI used by AN/SPG-62. Yes, the geometry is very narrow, you have to have the incoming targets in the same fairly narrow beam, but the USN knew that in a saturation missile attack by the Soviets there was a very high probability this geometry would be realized. ICWI is achieved by using different freqs for each SM-2, and dividing the time assigned to each missile. The resulting information each SM-2 receives is adequate to get the missile close enough to the target ( sufficiently accurate N calculation ) that the target will be inside the blast radius of the SM-2's warhead.

Ambivalent, you don't have ANY support of any kind for your now obviously fallacious claim that the SPG-62 is an ICWI illuminator. The main source that YOU yourself provided CONTRADICTS you. The Naval Institute Guide's section on the SPG-62 which I conveniently linked for you, CONTRADICTS you. BLUNTLY, might I add. At this point you have zero credibility and your pretense of insider military knowledge is all but completely shot. One rarely has evidence so unambiguous or so conclusive during internet debates, but this is very clearly a case where you are just dead wrong and yet have decided not to quit while you're behind.

crobato said:
There is no reason why you need ICW on the missile guidance itself. It is the main radar unit itself that needs it, and ICW is plainly redundant because you already have a pulse radar (SPY-1). Missile guidance doesn't rely on range information, it relies on unambiguous speed information which is provided already by CW.

The reason why APAR needs ICW---and it is the APAR that needs it, not the missile---is because APAR is not a pulse radar and therefore needs a system to obtain range. ICWI is intended to kill two birds with one stone---provide speed information for the missile guidance, while providing range information for the home radar set.

Having ICW on SPG-62 is possible but it is redundant and useless because SPY-1 is already a pulse radar and gets range info from the pulses. Putting ICW compatibility with SM-2 was intended for use from the beginning with non pulse search & tracking radars. AESA is not needed for ICW creation, but it still requires a specialized radar set with separate transmitters and receivers. If you put ICW on SPG-62, who is going to receive and process the range information? Not the missile itself, which only needs to recognize the signal, but not process the range information.

Again I repeat, ICWI is a shortcut between Pulse + CW. You don't need ICWI when you have already have pre-existing Pulse + CW sets. You want ICWI only when you consolidate two radar set functions into a single set, mainly tracking and illumination.

It is physically impossible for a mechancally steered radar to achieve ICWI on even just two targets. The source that Ambie conveniently provided for SDF's benefit also CLEARLY states so, and it's not hard to see why. A mechanically steered radar would have to achieve spot targeting on two different targets nearly simultaneously, meaning it has to alternate between one target and the other over time intervals on the order of microseconds. This cannot be achieved by the SPG-62 or any other non-ESA radar. Only electronically steered radar beams have the agility to rapidly shift back and forth from one target to another to achieve an interrupted illumination that is still useful to an SARH missile homing in on the reflected radar beams.

Incidentally, the Naval Institute Guide also says APAR is a pulse radar. Not only that, you can also find this on Google. Here is an unambiguous statement that APAR is monopulse like the SPY-1, and like essentially every other ESA:

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APAR doesn't use ICWI because it has to, it does so to increase the number of targets it can illuminate nearly simultaneously because the dwell time on each target is reduced with ICWI compared to CWI. A PESA illuminator, incidentally, would HAVE to use ICWI because as I said earlier the entire panel has only a single transmitter which is assigned to an entire quadrant of the sky. This transmitter would have to rapidly alternate between dozens to hundreds of targets in its quadrant to either track them or illuminate them. An AESA on the other hand could use CWI on many targets simultaneously because each panel contains thousands of individual transmitters which can then be further subgrouped by the computer and permanently assigned to different targets. Of course, this is wasteful since you don't need CWI on targets if your missile is capable of making due with ICWI. Actually theoretically each of the several thousand T/R modules on a given AESA panel could be individually and permanently assigned to a different target, though I'm certain there would be software/computing power limitations to such an approach.

Edit: I'm assuming a PESA with only a single TWT. PESA's with multiple TWT's controlling subgroups of transmitting elements on a PAR panel can result in a panel being able to send out multiple beams simultaneously, like an AESA. The PAC-3's radar for example is upgraded with an additional TWT compared to PAC-2, allowing an additional simultaneous beam to be generated for improved tracking and illumination. I reread the SPY-1D section in the Naval Institute Guide, and it looks like each of 4 panels on a Ticonderoga or Arleigh Burke has 8 transmitters, each controlling a subgroup of elements on a 4,096 element SPY-1D panel. Of course, each of these 8 transmitters on a side can track dozens of targets by time-sharing its beam over those targets, analogous to the way an ESA illuminator lights up multiple targets via ICWI.

crobato · Oct 27, 2009

Re: How Do You Sink A Carrier?

Being an ICWI has nothing to do with the ability to steer multiple beams at once. An SPG-62 can in paper, send one beam of ICWI (which is possible for testing purposes to be used with a true ICW set on another end product), but SPG-69 can only send one beam. At the same time, an AESA can send multiple beams of CW. Being CW or ICW has nothing to do multiple beam scanning. Wave form and beam scanning are two unrelated issues. Being parabolic, cassegrain, inverse cassegrain, slotted planar, passive phase array, or AESA is also unrelated to being pulse, FMCW, ICW or CW. You can create an old school parabolic antenna and still use ICW.

Oh, APAR is not pulse. Its monopulse. Monopulse and pulse have different meanings. An ICW imitates the conditions of a pulse by creating an interruption in the CW. By monopulse it means it can take four angular readings within one signal, instead of having to send a signal each for each reading. Meaning it only takes one scan to determine its position rather than the antenna having to move back and forth and do multiple scans to get the position. Your posted article says APAR is a monopulse is correct. Even a CW transmitter and receiver can be a monopulse. But a monopulse does not mean its a pulse radar. Monopulse is just a scanning technique to obtain angular position; its really a different topic from pulse-CW-ICW-FMCW discussions. We discuss monopulse in the context with helical scan (where the antenna spins) and conical scan (where the antenna rotates).

People are arguing over different areas of radar technologies as if they are related when are in fact, unrelated.

Wolverine · Oct 28, 2009

Re: How Do You Sink A Carrier?

crobato said:
Being an ICWI has nothing to do with the ability to steer multiple beams at once. An SPG-62 can in paper, send one beam of ICWI (which is possible for testing purposes to be used with a true ICW set on another end product)

Now you're starting to say the same thing Ambie is, which means both his source and Naval Institute Guide flatly and unambiguously say you're wrong. I don't know why the both of you keep talking like these sources either don't exist or have no weight compared to what you are posting, especially as neither of you have supporting sources to back yourselves up. The Naval Institute Guide flat out says that the SPG-62 is a CWI radar, and Ambie's source flat out says that Aegis illuminators are mechanical and employ CWI, and that they are too physically slow to employ ICWI. I believe too much "inertia" was the concept they were getting across.

And you're right about ICWI having nothing to do with multiple beams at once. I don't know what made you say that. I know I didn't say it. What I did say was that a PESA illuminator with only a single transmitter MUST use ICWI to illuminate mulitiple targets, and that an AESA illuminator CAN but does not HAVE TO use ICWI to illuminate multiple targets. I also said that mechanically steered illuminators CANNOT use ICWI, and this is supported by multiple sources, as I have stated multiple times.

You also seem to be confusing illumination with tracking, which are not equivalent concepts. ICWI is NOT "in between" CWI and pulse. Pulse has nothing to do with either ICWI or CWI. Illumination is just that, illumination. It neither provides any tracking information nor is the reflected illumination received or processed by the sending ship. All it does is paint the target for the SARH missile to home in on. Thus the SPG-62 provides the sending ship neither range, bearing, altitude or velocity, and it doesn't have to. Because that's not its job.

ICWI isn't pulsed or semi-pulsed, or pseudo-pulsed. ICWI is a CONTINUOUSLY emitted beam of radar that is rapidly cycled between different targets (which a mechanically steered radar is totally INCAPABLE of achieving). The "interrupted" part of it is not because the illuminator sends out beams in pulses, it's because the illumination is interrupted from the SARH missile's point of view in that it doesn't receive a constant paint on its target; instead it's like a sailor looking for a boat's progress by the light of a rotating lighthouse lamp, except that this lamp is able to light up the boat a few dozen times a second. This beam is CONTINUOUS from the lighthouse's point of view, not interrupted.

crobato said:
You can create an old school parabolic antenna and still use ICW.

No, you can't. What you probably mean is that an old school parabolic antenna can be pulsed, which is correct. ICWI has nothing to do with pulsing. The 'interruption' in "Interrupted Continuous Wave Illumination" is not from the emitter's POV, it's from the homing SARH missile's POV. It's still continuous, meaning it's a flashlight that's on all the time, except that you are just rapidly flicking it between several different targets (ICWI). You are not rapidly turning it on and off as you cycle between those targets (pulse). It does not, and does not have to, provide any form of tracking information.

crobato said:
Oh, APAR is not pulse.

Oh, but it is. It is pulse and monopulse. Page 265 of the Naval Institute Guide says this about APAR:

Pulses are emitted in bursts, with frequency and PRF fixed only within each dwell period of multiple bursts; variation in both parameters varies the clutter content of the burst.

You don't talk about pulsed repetition frequency with non-pulsed radars.

crobato · Oct 28, 2009

Re: How Do You Sink A Carrier?

I don't care what guide you are using. ICW has nothing to do with antenna. That's the result of the backend circuitry and TWT. ICW can be produced by anything capable of phase and frequency modulation, which are actually old technologies dated back to the fifties. A mechanical antenna can produce ICW, the means to produce the ICW are separate from the antenna.

If its pulsed, its not continuous wave. If its continuous wave, its not pulsed.

Pulse radars cannot be illuminators, because pulses gives ambiguous speed readings. If APAR is used for end guidance illumination, then that end guidance illumination is continuous wave, albeit modulated, and therefore cannot be pulse. Another thing, the backend circuitry of pulse and CW are quite different, so a pulse radar cannot produce CW and a CW radar cannot produce pulse. Furthermore, a CW radar is also structurally different because a CW radar requires a separate receiver, while a pulse radar uses the same antenna for both reception and emission, dividing them into timed cycles.

Put to you in another way, pulse and CW are a contradiction.

If Naval Institute Guide is saying APAR is pulse, I believe they're flat out wrong.

Now you're starting to say the same thing Ambie is, which means both his source and Naval Institute Guide flatly and unambiguously say you're wrong. I don't know why the both of you keep talking like these sources either don't exist or have no weight compared to what you are posting, especially as neither of you have supporting sources to back yourselves up. The Naval Institute Guide flat out says that the SPG-62 is a CWI radar, and Ambie's source flat out says that Aegis illuminators are mechanical and employ CWI, and that they are too physically slow to employ ICWI. I believe too much "inertia" was the concept they were getting across.

And you're right about ICWI having nothing to do with multiple beams at once. I don't know what made you say that. I know I didn't say it. What I did say was that a PESA illuminator with only a single transmitter MUST use ICWI to illuminate mulitiple targets, and that an AESA illuminator CAN but does not HAVE TO use ICWI to illuminate multiple targets. I also said that mechanically steered illuminators CANNOT use ICWI, and this is supported by multiple sources, as I have stated multiple times.

You also seem to be confusing illumination with tracking, which are not equivalent concepts. ICWI is NOT "in between" CWI and pulse. Pulse has nothing to do with either ICWI or CWI. Illumination is just that, illumination. It neither provides any tracking information nor is the reflected illumination received or processed by the sending ship. All it does is paint the target for the SARH missile to home in on. Thus the SPG-62 provides the sending ship neither range, bearing, altitude or velocity, and it doesn't have to. Because that's not its job.

ICWI isn't pulsed or semi-pulsed, or pseudo-pulsed. ICWI is a CONTINUOUSLY emitted beam of radar that is rapidly cycled between different targets (which a mechanically steered radar is totally INCAPABLE of achieving). The "interrupted" part of it is not because the illuminator sends out beams in pulses, it's because the illumination is interrupted from the SARH missile's point of view in that it doesn't receive a constant paint on its target; instead it's like a sailor looking for a boat's progress by the light of a rotating lighthouse lamp, except that this lamp is able to light up the boat a few dozen times a second. This beam is CONTINUOUS from the lighthouse's point of view, not interrupted.

I really think both of you don't know what Interrupted Continuous Wave is. Who told you it has something to do about being recycled rapidly between different targets?

The concept of ICW HAS NOTHING to do with targeting at all.

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"A continuous wave that is interrupted at a constant audio-frequency rate high enough to give several interruptions for each keyed code dot. Abbreviated ICW."

In other words, you got a continuous wave that is being frequency and phase modulated to create regular interruptions. The reason for this interruptions is because you are getting your range readings based on those interruptions. Those range readings are used by the base radar set, not by the missile itself.

A mechanical parabolic like the SPG-69 has only one beam and can light one target, period. That beam is CW. Even if that beam is made ICW, it will still only light one target. The only purpose that ICW gives is to provide range information to a radar set, which the SPG-69 is not equipped with.

And no, it does not work like a lighthouse. Rather, something like APAR projects several beams at once. each beam lighting the target. It does not interrupt the beam to light one target at a time in time sharing fashion, as that is really no different from pulse and would give ambiguous readings. It also defeats the purpose of continuous wave as the reflection from the target is what is needed to be continuous, not from the source.

Wolverine · Oct 29, 2009

Re: How Do You Sink A Carrier?

crobato said:
I don't care what guide you are using.

Clearly you know neither the noted expert Norman Friedman nor his 843 page Naval Institute Guide, the Bible of naval combat systems, a new edition of which appears every few years. We are now on the 5th edition. His writing gets as close to Final Word as open literature can get. Disagreeing with him is like disagreeing with Stephen Hawking on the details of quantum mechanics. Then there's you, a random internet poster. And I'm going to take your opinion over his? I think not. Not to mention you have no sources at all stating that the SPG-62 can employ ICWI. NONE. Not a single one. Or you would have produced it by now. I have two sources that say it's CWI, one of which is Norman Friedman himself, the other of which is provided, humorously enough, by Ambie. I could list more, but let's face it, I don't need any more. You on the other hand are just giving your incorrect opinion. You can continue to give your incorrect opinion in face of all reality and in the face of unambiguous and reliable evidence, and I suspect you will keep doing so, but that's all it will be. It doesn't matter how many times you say it or how many ways you say it. It would still be wrong.

crobato said:
ICW has nothing to do with antenna. That's the result of the backend circuitry and TWT. ICW can be produced by anything capable of phase and frequency modulation, which are actually old technologies dated back to the fifties. A mechanical antenna can produce ICW, the means to produce the ICW are separate from the antenna.

No, it simply can't. See above. End of story.

crobato said:
If its pulsed, its not continuous wave. If its continuous wave, its not pulsed.

That's right. So what? A pulsed beam is not a CW beam. That is self-evident.

crobato said:
Pulse radars cannot be illuminators, because pulses gives ambiguous speed readings.

Wrong. Pulse radars CAN be illuminators. RADARS CAN HAVE DIFFERENT MODES. This basic piece of knowledge is so basic that the fact that you do not know this does not bode well for your credibility. Aircraft radars for example, even the older pulse ones, have both CW and pulse functions. The AN/AWG-9 of the F-14 for example, can perform both TWS with pulse (for its Phoenixes) and illumination with CW (for its Sparrows). In fact it has many pulse modes. It has 2 TWTs, one assigned to CWI emission and one assigned to pulse emission.

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Similarly, the APAR panel

is divided into four independent quadrants, each of which has its own waveform generator and two missile guidance waveform generators (for both the missile uplink and terminal illumination).

Naval Institute Guide, p. 265

I have already demonstrated that you were incorrect in claiming that the APAR is not a pulse radar. Now I have also provided evidence that as a pulse radar it can provide terminal illumination, and that the two modes are not mutually exclusive in the same radar. Since we already have multiple other sources that states that APAR missile guidance is via ICWI, it is clear the APAR can both track by pulse and illuminate by ICWI.

Another thing, the backend circuitry of pulse and CW are quite different, so a pulse radar cannot produce CW and a CW radar cannot produce pulse. Furthermore, a CW radar is also structurally different because a CW radar requires a separate receiver, while a pulse radar uses the same antenna for both reception and emission, dividing them into timed cycles.

Put to you in another way, pulse and CW are a contradiction.

Clearly your understanding of pulse and CW are in error, including all that stuff that you just said about hardware. The only hardware required is a TWT. The structure of the radar is unchanged. And actually, a CW illuminator like the SPG-62 doesn't need ANY receiver at all. It's an emitter pure and simple. The only thing that "receives" its emissions is the SM-2.

If Naval Institute Guide is saying APAR is pulse, I believe they're flat out wrong.

You can believe whatever you like, but you're still incorrect. If not, I invite you to provide a link which says that the same radar CANNOT emit both pulse and CW. In fact I invite you to provide links for all of those other claims that you have left unsupported so far and which are flat out contradicted by respected sources which I HAVE provided, like the claim that the SPG-62 can employ ICWI, that APAR is not a pulse radar, or that the physical structure of radars that emit CWI and those that emit pulses are different.

I really think both of you don't know what Interrupted Continuous Wave is.

I really think you don't have the qualifications to make that statement.

Who told you it has something to do about being recycled rapidly between different targets?

The concept of ICW HAS NOTHING to do with targeting at all.

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"A continuous wave that is interrupted at a constant audio-frequency rate high enough to give several interruptions for each keyed code dot. Abbreviated ICW."

In other words, you got a continuous wave that is being frequency and phase modulated to create regular interruptions. The reason for this interruptions is because you are getting your range readings based on those interruptions. Those range readings are used by the base radar set, not by the missile itself.

No. This statement does not say that there is any ANY frequency or phase "modulation", rather that the signal is interrupted at a constant rate. This is your attempt to read your own misconception into this statement. And why does an illumination beam have any need of range readings, especially from a radar that is completely slaved to another radar that provides all the tracking information already, including range information? The answer is that it doesn't need range information, it doesn't do any pulsing of any kind, and it doesn't do any ICWI, which has nothing to do with ranging or pulsing.

A mechanical parabolic like the SPG-69 has only one beam and can light one target, period. That beam is CW. Even if that beam is made ICW, it will still only light one target. The only purpose that ICW gives is to provide range information to a radar set, which the SPG-69 is not equipped with.

Another unsupported claim. Provide a link that states ICWI provides any range information at all. Provide a link that states the SPG-69 can even be made ICWI.

And no, it does not work like a lighthouse. Rather, something like APAR projects several beams at once. each beam lighting the target. It does not interrupt the beam to light one target at a time in time sharing fashion, as that is really no different from pulse and would give ambiguous readings. It also defeats the purpose of continuous wave as the reflection from the target is what is needed to be continuous, not from the source.

Again, you do not understand ICWI. Let me repeat Ambie's source:

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The fire control radars that are now used as illuminators, including Aegis, employ a large mechanical antenna to generate a simple "pencil beam" of electromagnetic energy that illuminates a single target. The large antenna that forms this narrow beam must be precisely stabilized to compensate for both the ship's and the target's motion. Because of its large inertia, the mechanical antenna cannot be used as an ICW multi-target illuminator.

This is lifted straight from the text. What does inertia have to do with pulsing? NOTHING. What does inertia have to do with ICWI? EVERYTHING. A mechanically steered radar like the SPG-62 cannot physically perform the rapid beam shifting from one target to another that "multi-targeting" ICWI requires, and is, again, something only an electronically steered, agile beam can accomplish.

It goes on to say this:

ICW. This technique permits a single fire control radar to control two or more missiles simultaneously in the final phase of their flight. Engineers now believe it may not be necessary for semi-active AAW missiles to receive continuous terminal illumination. Just as a motion picture is composed of a series of discrete still pictures, a series of discrete illumination pulses could be rapidly switched among multiple targets, providing the necessary homing energy to guide several AAW missiles to their individual targets. If, in fact, interception can be achieved with illumination for less than 50 percent of the time during terminal guidance, then two targets might be engaged simultaneously with a single fire control radar. If that requirement could be reduced still further to less than 25 percent, then four targets could be engaged, etc., thus multiplying firepower.

The meaning of these passages is clear enough. You are simply refusing to acknowledge the obvious conclusion that you do not have a correct understanding of what ICWI is.

bd popeye · Oct 29, 2009

Discuss military radar, sonar and other military sensors in this thread.

Because I know nothing about such things

I hope one of the other mods steps in and moderates the discussion..

I've moved several post from the sink your CV thread to this discussion.Enjoy.

crobato · Oct 29, 2009

Re: How Do You Sink A Carrier?

Wolverine said:
Clearly you know neither the noted expert Norman Friedman nor his 843 page Naval Institute Guide, the Bible of naval combat systems, a new edition of which appears every few years. We are now on the 5th edition. His writing gets as close to Final Word as open literature can get. Disagreeing with him is like disagreeing with Stephen Hawking on the details of quantum mechanics. Then there's you, a random internet poster.

That's the problem with you. You take books too seriously. You are applying religious thinking on a scientific subject. When you take a book and apply it like a dogma, you're no longer dealing with technology. You are assuming that Norman Friedman, who doesn't strike me as understanding radar technologies, is infallible as the Pope.

If you are serious into technology, the basis of science, engineering and technology has always been skepticism.

If the book is wrong, its wrong. The best sources can have all sorts of errors.

And I'm going to take your opinion over his? I think not. Not to mention you have no sources at all stating that the SPG-62 can employ ICWI. NONE. Not a single one. Or you would have produced it by now. I have two sources that say it's CWI, one of which is Norman Friedman himself, the other of which is provided, humorously enough, by Ambie. I could list more, but let's face it, I don't need any more. You on the other hand are just giving your incorrect opinion. You can continue to give your incorrect opinion in face of all reality and in the face of unambiguous and reliable evidence, and I suspect you will keep doing so, but that's all it will be. It doesn't matter how many times you say it or how many ways you say it. It would still be wrong.

I never said that the SPG-62 is ICW. I only said ICW can be in theory, implemented on the SPG-62 just for the sake of trials, with the final end user being that of a separate ICW unit in a separate ship.

Wrong. Pulse radars CAN be illuminators. RADARS CAN HAVE DIFFERENT MODES. This basic piece of knowledge is so basic that the fact that you do not know this does not bode well for your credibility. Aircraft radars for example, even the older pulse ones, have both CW and pulse functions. The AN/AWG-9 of the F-14 for example, can perform both TWS with pulse (for its Phoenixes) and illumination with CW (for its Sparrows). In fact it has many pulse modes. It has 2 TWTs, one assigned to CWI emission and one assigned to pulse emission.

BULL. Get a basic knowledge of radar electronics. CW and pulse requires different hardwired circuitry. Its not software selectable. The AWG-9 has a separate illuminator from the pulse radar.

When the AWG-9 illuminates the target, the pulse radar is still functioning separately, and the illuminator is slaved to the tracking function of the pulse radar.

If pulse -> CW change is mere software modal, once the radar set goes into CW, the radar set becomes blind since under CW conditions, the radar does not receive anything.

I have already demonstrated that you were incorrect in claiming that the APAR is not a pulse radar. Now I have also provided evidence that as a pulse radar it can provide terminal illumination, and that the two modes are not mutually exclusive in the same radar. Since we already have multiple other sources that states that APAR missile guidance is via ICWI, it is clear the APAR can both track by pulse and illuminate by ICWI.

LOL your description does not indicate a pulse radar. It only indicates monopulse directional finding.

APAR does not pulse, simple as that. At least not like the SPY-1 where the energy is collected, then sent out in a single high power burst. APAR "pulses" by going on-off on its continuous wave.

You can believe whatever you like, but you're still incorrect. If not, I invite you to provide a link which says that the same radar CANNOT emit both pulse and CW. In fact I invite you to provide links for all of those other claims that you have left unsupported so far and which are flat out contradicted by respected sources which I HAVE provided, like the claim that the SPG-62 can employ ICWI, that APAR is not a pulse radar, or that the physical structure of radars that emit CWI and those that emit pulses are different.

I will let you hang on to the statement there, so it can haunt you in the future.

Sorry, but you have not provided links that confirm that pulse radar circuit can be CW. Start googling around with radar basics, will you?

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I really think you don't have the qualifications to make that statement.

And you far less.

Another unsupported claim. Provide a link that states ICWI provides any range information at all. Provide a link that states the SPG-69 can even be made ICWI.

LOL. I think you need to learn about modulated CWI.

This is lifted straight from the text. What does inertia have to do with pulsing? NOTHING. What does inertia have to do with ICWI? EVERYTHING. A mechanically steered radar like the SPG-62 cannot physically perform the rapid beam shifting from one target to another that "multi-targeting" ICWI requires, and is, again, something only an electronically steered, agile beam can accomplish.

The SPG-62 cannot do rapid beam shifting from one target to another over a wide quadrant but not within a small FOV.

Still, there is nothing there that says SPG-62 can be backend modded for ICW for testing purposes with the end result intended for other customers like APAR ships. You tell me how the hell they're going to test the missiles simultaneously while APAR is still in development?

It goes on to say this:

ICW. This technique permits a single fire control radar to control two or more missiles simultaneously in the final phase of their flight. Engineers now believe it may not be necessary for semi-active AAW missiles to receive continuous terminal illumination. Just as a motion picture is composed of a series of discrete still pictures, a series of discrete illumination pulses could be rapidly switched among multiple targets, providing the necessary homing energy to guide several AAW missiles to their individual targets. If, in fact, interception can be achieved with illumination for less than 50 percent of the time during terminal guidance, then two targets might be engaged simultaneously with a single fire control radar. If that requirement could be reduced still further to less than 25 percent, then four targets could be engaged, etc., thus multiplying firepower.

The meaning of these passages is clear enough. You are simply refusing to acknowledge the obvious conclusion that you do not have a correct understanding of what ICWI is.

Sigh. What you describe here only says ICW permits doing this, but its not a definition. That's like defining a bird because it flies. It only says ICW permits time sharing. [An AESA CW illuminator can also send multiple beams and light up targets continuously without need for interruption on the CW].

It does not tell you the entire story. Considering that no other radar on the ship is capable of fast, precise tracking, APAR must also do multiple target tracking. Who is also going to guide these beams to the targets? The APAR does double duty as both tracking radar and target illuminator. The reflections goes to the missile for terminal guidance and at the same time, goes to the base radar itself to provide range and tactical information for the operators.

With a pure CW, the information you get from the echo only tells you of direction and speed, but not range. With modulated CW, it adds range.

Modulated CW creates a condition similar to pulse, and for all intents and purposes, functionally similar to a true pulse radar. So in a way, APAR is a "pulse" radar but it is not a true pulse radar like the SPY-1, since SPY-1 does not create pulses out of modulation by staggering the wave form in long plateaus and valleys, but with a true send-receive-send-receive duty cycles created by timing.

The tactical difference of "pulse" ICW vs. true pulse like the SPY-1 is that pulse radar has a much greater range due to the peak power, but that high peak power also makes it more detectable. Please note the hardware has to be different from the two since in a pulse power, during the receive cycle of the radar, the electrical energy collected during the period is stored into capacitors, then emitted in a "burst". In ICW, this is not the case. The wave is modulated to have a high plateau and long valley, sometimes like a trapezoid or a square.

Here is again, the meaning of interrupted continuous wave illumination.

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interrupted continuous wave (ICW): Modulation n which there is on-off keying of a continuous wave.

Did it say interrupt by beam steering away? Interrupt by time sharing? No. It specifically said modulation.

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PULSE OR INTERRUPTED CONTINUOUS WAVE DEMODULATOR:

(under the class definition) Subject matter where the demodulator extracts the modulating signal from a modulated signal which has undergone pulse modulation.

(1) Note. Pulse modulation occurs when a repetitious pulse wave has a characteristic varied in accordance with the modulating signal.

(2) Note. Interrupted continuous wave modulation occurs when a pulsed continuous wave has a characteristic varied in accordance with the modulating signal.

(3) Note. Examples of pulse waves are square waves, sawtooth waves, and trapezoidal waves.

(4) Note. Comparable structure having an input which is pulse code modulated (PCM) or delta modulated are found elsewhere. See the Search Notes below.

(5) Note. This subclass includes pulse demodulators, per se. See the SEARCH CLASS notes below for combinations with the subject matter of this subclass.

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More on circuitry differences.

"CW radars are far less complex than pulsed systems because they don't have all the clocking circuitry and high frequency switching devices of low-, medium- or high-PRF radars. Their transmitter hardware is less expensive because there is no need for high power devices capable of handling signals in the megawatt range for the duration of a microsecond. The magnetron taken out of your microwave oven could do the job nicely. "

Again, do note that CW radars must have separate receivers and transmitting elements while a pulse radar does not.

Range determination. There are different means of modulation. FM is one of them. Whatever the means of modulation, whether its frequency, pulse or phase, the idea is to create variations upon the wave to create distinct markers that are used for range measurement.

"This is a continuous wave signal but it has frequency variations on it. Therefore it is called 'Frequency Modulated CW', or FMCW in short. Just as in a pulsed radar, ranging is feasible by comparing the transmitted signal and the echo which is basically a time-delayed replica. Of course, the length of each 'up-sweep' or 'down-sweep' must be chosen carefully to avoid misinterpretations regarding which part of the signal had caused which part of the echo - there is a need to take care of range ambiguities. "

Wolverine · Oct 30, 2009

Re: How Do You Sink A Carrier?

crobato said:
That's the problem with you. You take books too seriously. You are applying religious thinking on a scientific subject. When you take a book and apply it like a dogma, you're no longer dealing with technology. You are assuming that Norman Friedman, who doesn't strike me as understanding radar technologies, is infallible as the Pope.

If you are serious into technology, the basis of science, engineering and technology has always been skepticism.

If the book is wrong, its wrong. The best sources can have all sorts of errors.

I never said that the SPG-62 is ICW. I only said ICW can be in theory, implemented on the SPG-62 just for the sake of trials, with the final end user being that of a separate ICW unit in a separate ship.

There is no dogma involved. You can spin this into some kind of dogmatic thing all you want, but the facts on the ground are that an expert has flatly contradictly you, and you have NOBODY to back you up. A well-respected volume contradicting a random internet poster. It's not even a fair fight. You have not produced even a SINGLE source this entire time that states the SPG-62 is capable of ICWI. Not a single one. None. Nada. Zip. Zilch. Squat. You are just a random internet poster, and as far as I'm concerned, if your totally unsupported personal opinion contradicts a known source (not to mention if you've shown many times that you don't understand ICWI, and you have), then you're flat out wrong. End of story.

crobato said:
BULL. Get a basic knowledge of radar electronics. CW and pulse requires different hardwired circuitry. Its not software selectable. The AWG-9 has a separate illuminator from the pulse radar.

When the AWG-9 illuminates the target, the pulse radar is still functioning separately, and the illuminator is slaved to the tracking function of the pulse radar.

If pulse -> CW change is mere software modal, once the radar set goes into CW, the radar set becomes blind since under CW conditions, the radar does not receive anything.

BULL. YOU get a basic knowledge of radar electronics. You now have yet ANOTHER source that flatly contradicts you, and all you can do is act arrogant, bluster, and tell the world it doesn't know what it's talking about. It's becoming a pattern with you. There is NOTHING on that AWG-9 page that says there is a separate illuminating radar apart from the AWG-9 itself. What it does say is that a separate TWT is dedicated to each of CW and pulse functions. That is also what the Naval Institute Guide says about the APAR. It's still the same exact radar in both cases. Actually that makes it TWO sources that flatly contradict what you say. And what evidence do you have to support your personal opinion? The answer once again, is NOTHING. NOTHING. You have NOTHING but your own words. You can wail and thunder until you're blue in the face, but if every source flatly contradicts what you say, you should consider that you are now arguing purely out of ego rather than out of the pursuit of knowledge. That's what this forum is about, after all.

crobato said:
LOL your description does not indicate a pulse radar. It only indicates monopulse directional finding.

APAR does not pulse, simple as that. At least not like the SPY-1 where the energy is collected, then sent out in a single high power burst. APAR "pulses" by going on-off on its continuous wave.

So why does the Naval Institute Guide's description on APAR talk about its operation of PRF (pulse repetition frequency), if it does not pulse? PRF is a term specific to pulsing radars. And what evidence besides your own personal opinion do you have that APAR is not a pulse radar? Once again, the pattern holds, and the answer is NOTHING. Here, educate yourself about PRF:

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Note that it is instrumental in allowing pulse radars to range a target, something that I note you're a big fan of. And incidentally, something that your source "Radar systems analysis and design" talks about in reference to pulse rdars but NOT in reference to CW radars. Oops, did you just shoot yourself in the foot? Not only that, I used the search function to look for ICWI, and guess what? NOWHERE is ICWI mentioned. You have been trying to front like ICWI is like some kind of intermediate mode of pulsation that is somehow "in between" pulse and CW. If that were actually the case, this book (published in 2000 BTW) would certainly have made mention of that. But it doesn't. Why? Clearly because ICW IS CW. It is nothing more than a manner in which CW can be employed (i.e. rapidly cyling a CW radar between different targets in a military application). And since the underlying concept of ICW is CW, there is thus nothing new to talk about from a book on basic radar principles, and thus no mention of ICWI in this book. It is not some silly intermediate concept between pulse and CW.

crobato said:
Sorry, but you have not provided links that confirm that pulse radar circuit can be CW. Start googling around with radar basics, will you?

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And what is there to say in that source of yours that a single radar cannot have circuitry for both pulse and CW integrated into one physical system? NOTHING. Not only that, the sources I have provided indicate this is EXACTLY what's happening in both AWG-9 and the APAR, ie they both have pulse and CW functions in a single system without mention of any auxiliary illuminating systems. In fact, they say that radar functions have nothing more than separate TWT modules dedicated to pulse and to CW. How much do you want to bet that I can find more descriptions of pulse radars with illuminating functions that make absolutely NO mention of any separate illuminating radar systems?

You have been shown to be so flat out wrong about so many things on this topic, including now from this source, that it's now getting ridiculous.

crobato said:
And you far less.

LOL

crobato said:
The SPG-62 cannot do rapid beam shifting from one target to another over a wide quadrant but not within a small FOV.

What in the world are you trying to say here? What evidence do you have that this is the case besides your own totally unsupported personal opinion on this issue, which we now can see is rather lacking in credibility?

crobato said:
Still, there is nothing there that says SPG-62 can be backend modded for ICW for testing purposes with the end result intended for other customers like APAR ships. You tell me how the hell they're going to test the missiles simultaneously while APAR is still in development?

What? "Backend modded" for "testing purposes"? It's clear that you are now desperately grasping for straws here.

crobato said:
Sigh. What you describe here only says ICW permits doing this, but its not a definition. That's like defining a bird because it flies. It only says ICW permits time sharing. [An AESA CW illuminator can also send multiple beams and light up targets continuously without need for interruption on the CW].

What a ludicrous attempt at spinning this obvious source. It describes EXACTLY what ICW is by describing how SARH missiles do not need a continuous lighting up of their targets and can receive adequate targetting information by receiving intermittent 'screen shots'. This is just AFTER it describes how mechanically steered CW cannot do this, and just BEFORE it describes how electronically steered ICW does exactly this. If mechanically steered illuminators like the SPG-62 CAN do ICWI, why does this source flatly say they cannot? Why does this source talk about "inertia" as the reason that mechanically steered illuminators cannot do ICWI? If your conception of ICWI as some kind of 'intermediate' between pulse and CW is correct, what does inertia have anything to do with whether a radar can or cannot do ICWI? The answer is NOTHING. NOTHING because ICWI is NOT 'intermediate' between pulse and CW, whatever the hell that means. And again, "inertia" has EVERYTHING to do with ICWI because ICWI requires rapid cycling between several distinct objects in the sky which a mechanically steered illuminator cannot physically do, because of "inertia", the principle that an object moving in a certain direction tends to keep moving in that direction. The micromotions that would be required of the motors on the SPG-62 to nearly simultaneously paint multiple targets is impossible to achieve. That's what this source is saying. Actually you know all this. You are simply refusing to acknowledge the obvious facts that are flying in your face.

crobato said:
It does not tell you the entire story. Considering that no other radar on the ship is capable of fast, precise tracking, APAR must also do multiple target tracking. Who is also going to guide these beams to the targets? The APAR does double duty as both tracking radar and target illuminator. The reflections goes to the missile for terminal guidance and at the same time, goes to the base radar itself to provide range and tactical information for the operators.

Did you just ignore where my source said that APAR has separate TWTs dedicated to tracking and illuminating? Not separate radars, separate transmitters, SAME radar, using separate TWT's to track and illuminate, on the same facing PAR panel. There is no pseudo-semi-pulsing simultaneously tracking/illuminating magical beam coming out of the APAR, that exists only in your imagination.

crobato said:
With a pure CW, the information you get from the echo only tells you of direction and speed, but not range. With modulated CW, it adds range.

Modulated CW creates a condition similar to pulse, and for all intents and purposes, functionally similar to a true pulse radar. So in a way, APAR is a "pulse" radar but it is not a true pulse radar like the SPY-1, since SPY-1 does not create pulses out of modulation by staggering the wave form in long plateaus and valleys, but with a true send-receive-send-receive duty cycles created by timing.

Did you just find out about the concept of FMCW in your Googling or something? Think it will allow you to spin your way out of a losing battle? FMCW is not ICW. There is nothing "interrupted" about FMCW. Is this why you dropped 'frequency' from your post? After all 'modulated' CW to someone who doesn't know does sound kinda like 'interrupted' CW. Do you even know the difference yourself? If so, why even bring up modulated CW?

Down towards the middle of the page:

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By the way, ONCE AGAIN you have NO source stating that APAR is not a "true" pulse radar except your own personal opinion. If you understood even the basics of PRF, you wouldn't be saying that.

crobato said:
The tactical difference of "pulse" ICW vs. true pulse like the SPY-1 is that pulse radar has a much greater range due to the peak power, but that high peak power also makes it more detectable. Please note the hardware has to be different from the two since in a pulse power, during the receive cycle of the radar, the electrical energy collected during the period is stored into capacitors, then emitted in a "burst". In ICW, this is not the case. The wave is modulated to have a high plateau and long valley, sometimes like a trapezoid or a square.

You've directly said that they not only have to have distinct circuitry, they in fact have to be two entirely separate radars. And didn't I show you two radars that both emit both pulse and CW? Oops for you. Sorry, NO mention of separate illuminating radars in either of those two radar systems. LOTS of mention of dedicated TWTs in those same radar systems. Oops, oops, oops.

crobato said:
Here is again, the meaning of interrupted continuous wave illumination.

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interrupted continuous wave (ICW): Modulation n which there is on-off keying of a continuous wave.

Did it say interrupt by beam steering away? Interrupt by time sharing? No. It specifically said modulation.

BULL. This use of the word modulation is not a technical use of modulation, as in FMCW, no matter how you try to spin this one-liner of a definition. It does say on off keying of a CW. That's EXACTLY what it does to a target. That's EXACTLY what an SARH missile sees as it homes in on that target. FMCW doesn't key ANYTHING on or off. It's a CONTINUOUS wave whose frequency is modulated to provide ranging. NOTHING is being interrupted or being keyed on or off. You couldn't possibly stretch or spindoctor the definition of either "interrupted" or "on-off keying" to somehow encompass 'frequency modulation of a continuous wave'. On the other hand, like I said, ICWI as I and basically every other description has said, does in fact "key on and off" a target as it cycles between multiple targets. It does in fact "interrupt" its illumination of its assigned targets by illuminating the next target in the cycle. ONCE AGAIN, you are attempting to impart your own misconception of ICWI into this definition.

crobato said:
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.....
(2) Note. Interrupted continuous wave modulation occurs when a pulsed continuous wave has a characteristic varied in accordance with the modulating signal.
.....

LOL. I don't know how this source could possibly help you. Weren't you the one who said

If its pulsed, its not continuous wave. If its continuous wave, its not pulsed.

and this?

Put to you in another way, pulse and CW are a contradiction.

And yet we have a curious statement that a "pulsed continuous wave has a characteristic varied in accordance with the modulating signal". Since according to you, you CAN'T have a pulsing CW, are you now contradicting your own source? How will you spin this one? Nor, and importantly, does it make ANY mention of frequency modulation, an important thing to mention, one would think, as part of a definition of ICW, if in fact ICW = FMCW. Clearly either you're just dead wrong or this source is using words like "pulsed" or "modulation" in ways we aren't, or both. I vote for the last of the three possibilities.

crobato said:
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More on circuitry differences.

"CW radars are far less complex than pulsed systems because they don't have all the clocking circuitry and high frequency switching devices of low-, medium- or high-PRF radars. Their transmitter hardware is less expensive because there is no need for high power devices capable of handling signals in the megawatt range for the duration of a microsecond. The magnetron taken out of your microwave oven could do the job nicely. "

Again, do note that CW radars must have separate receivers and transmitting elements while a pulse radar does not.

Once again, who says that CW and pulse functions cannot be integrated into a single radar, hardware, software and all? In fact I've already shown you this is exactly what has happened with these military radars, which have need of both functions in a compact space. Thus the AWG-9 in a single radar has both pulse and CW functions, and the APAR has both pulse and CW functions. You tried to brush off the grossly contradictory AWG-9 source (contradictory for you) by trying to claim WITH ABSOLUTELY ZERO EVIDENCE that there is some kind of separate CW illuminating radar that's not the AWG-9 itself. That's essentially like claiming there is a little genie inside there emitting CW on command. You may get away with making blatantly wrong and unsupported statements in other threads, but not in this one.

crobato said:
Range determination. There are different means of modulation. FM is one of them. Whatever the means of modulation, whether its frequency, pulse or phase, the idea is to create variations upon the wave to create distinct markers that are used for range measurement.

"This is a continuous wave signal but it has frequency variations on it. Therefore it is called 'Frequency Modulated CW', or FMCW in short. Just as in a pulsed radar, ranging is feasible by comparing the transmitted signal and the echo which is basically a time-delayed replica. Of course, the length of each 'up-sweep' or 'down-sweep' must be chosen carefully to avoid misinterpretations regarding which part of the signal had caused which part of the echo - there is a need to take care of range ambiguities. "

Yeah, this is a description of FMCW. So what? Frequency modulation doesn't have any interruptions in it because it's still a continuous wave no matter how you try to spin the word "modulation" to make it sound like "interruption". Your attempt to equate FMCW with ICW is clearly a newly developed front which you coalesced over the last two posts and which you initially did not have knowledge of, or you would have attempted this spin from the very beginning. It's not working.

You know, I don't know why I didn't think of this before. I searched "interrupted continuous wave illumination" using Googlebooks and look at the treasure trove I found.

From Introduction to Electronic Defense Systems By Filippo Neri

The target is illuminated by an interrupted continuous wave. This means that a single system can launch missiles against several targets. Therefore radar and illuminator must both be capable of pointing the antenna beam successively and rapidly at the various targets. This is achieved by using tracking radars with phased-array antennas.

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Here is another one:
From Radar Handbook By Merrill Ivan Skolnik

To overcome the limitation of tying up an illuminator for the duration of a semiactive engagement, a single radar can be time-shared among several missiles. This generally implies a phased array radar, although mechanically scanned track-while-scan (TWS) radars can provide this option in some cases. The advent of phased array radars permitted a single radar to illuminate many targets by sequentially stepping its agile beam from one target to the next. The illumination was no longer continuous, and the missile would thus have to operate in a sampled-data mode, extracting information during the time that its target was illuminated (dwell time) and then holding the information until the next sample.

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These constitute yet another TWO additional authoritative source that flatly contradicts your claims about what ICWI is. And yet we have you saying this:

The concept of ICW HAS NOTHING to do with targeting at all.

And this:

Did it say interrupt by beam steering away? Interrupt by time sharing? No. It specifically said modulation.

And this:

Even if that beam is made ICW, it will still only light one target. The only purpose that ICW gives is to provide range information to a radar set, which the SPG-69 is not equipped with.

And no, it does not work like a lighthouse.

Yes, it in fact DOES work like a lighthouse. BTW, what in the world is an "SPG-69"?

And here's two more sites indicating ICWI is ALL about targeting (multi-target engagement), not what's being emitted (CW).

The new ICWI concept allows the user to simultaneously control multiple missiles with one Apar radar, whereas earlier systems require separate radars for each engaged target.

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Straight from the horse's mouth (Thales):

ICWI (Interrupted Continuous Wave Illumination) is a technology that enables a missile control system to guide several missiles simultaneously to various threats, greatly enhancing a ship's defence capabilities.

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Wolverine · Oct 30, 2009

Redundant post (merged into previous post).

crobato · Oct 30, 2009

Re: How Do You Sink A Carrier?

Wolverine said:
There is no dogma involved. You can spin this into some kind of dogmatic thing all you want, but the facts on the ground are that an expert has flatly contradictly you, and you have NOBODY to back you up. A well-respected volume contradicting a random internet poster. It's not even a fair fight. You have not produced even a SINGLE source this entire time that states the SPG-62 is capable of ICWI. Not a single one. None. Nada. Zip. Zilch. Squat. You are just a random internet poster, and as far as I'm concerned, if your totally unsupported personal opinion contradicts a known source (not to mention if you've shown many times that you don't understand ICWI, and you have), then you're flat out wrong. End of story.

LOL. Really. Show me an expert that really contradicted me.

There is nothing there---I would agree with Ambi here---that SPG-62 cannot be made to pulse modulate its CWI by keying the signal on and off.

Do you know how that works? Yes. Simply by stopping the signal intervals.

BULL. YOU get a basic knowledge of radar electronics. You now have yet ANOTHER source that flatly contradicts you, and all you can do is act arrogant, bluster, and tell the world it doesn't know what it's talking about. It's becoming a pattern with you. There is NOTHING on that AWG-9 page that says there is a separate illuminating radar apart from the AWG-9 itself. What it does say is that a separate TWT is dedicated to each of CW and pulse functions.

LOL. I never said that its an illuminating radar. Do you know what an illuminator is? An illuminator is not a radar.

RADAR. RAdio Detecting And Ranging.

You really don't know WTF Radar is don't you. You don't even understand the nature of the term.

The illuminator is not a radar. Technically a radar also detects (receiving function) and from it obtains range.

A CW illuminator is not a radar. That separate TWT is the illuminator.

Like you don't understand the very text of what is being said.

That is also what the Naval Institute Guide says about the APAR. It's still the same exact radar in both cases. Actually that makes it TWO sources that flatly contradict what you say. And what evidence do you have to support your personal opinion? The answer once again, is NOTHING. NOTHING. You have NOTHING but your own words. You can wail and thunder until you're blue in the face, but if every source flatly contradicts what you say, you should consider that you are now arguing purely out of ego rather than out of the pursuit of knowledge. That's what this forum is about, after all.

Again, you don't know the basic difference between a pulse radar and a CW radar.

Pulse radar - sends and receives on the same antenna.

CW radar - sends and receives on two separate antenna.

So why does the Naval Institute Guide's description on APAR talk about its operation of PRF (pulse repetition frequency), if it does not pulse? PRF is a term specific to pulsing radars. And what evidence besides your own personal opinion do you have that APAR is not a pulse radar? Once again, the pattern holds, and the answer is NOTHING. Here, educate yourself about PRF:

What a joke. When you interrupt a continuous wave, the square form of the wave can be regarded as functionally as the pulse.

Did you read the BBC definition? A continuous wave can also be regarded as infinite PRF.

Note that it is instrumental in allowing pulse radars to range a target, something that I note you're a big fan of. And incidentally, something that your source "Radar systems analysis and design" talks about in reference to pulse rdars but NOT in reference to CW radars. Oops, did you just shoot yourself in the foot? Not only that, I used the search function to look for ICWI, and guess what? NOWHERE is ICWI mentioned. You have been trying to front like ICWI is like some kind of intermediate mode of pulsation that is somehow "in between" pulse and CW. If that were actually the case, this book (published in 2000 BTW) would certainly have made mention of that. But it doesn't. Why? Clearly because ICW IS CW. It is nothing more than a manner in which CW can be employed (i.e. rapidly cyling a CW radar between different targets in a military application). And since the underlying concept of ICW is CW, there is thus nothing new to talk about from a book on basic radar principles, and thus no mention of ICWI in this book. It is not some silly intermediate concept between pulse and CW.

Sigh. Did you read the sources actually?

ICW is merely "interrupted" CW. Its CW where you put "offs". Its the equivalent of a faucet with running water, and where you turn the water on and off.

And what is there to say in that source of yours that a single radar cannot have circuitry for both pulse and CW integrated into one physical system? NOTHING.

That's because you did not bother to actually read it. With a true pulse radar, the pulses are created through an oscillator. The difference between a true pulse radar and ICW is that the pulses are not created through keyed on off or frequency modulation.

In the pulse radar, the circuitry stores up the energy then send out in one burst. Pulse radar is characterized by high peak power. It requires only one antenna, where is cycled into send and receive periods.

In modulated CW, the CW is modulated to create different forms (square, trapezoidal) to act like a pulse. CW is characterized by low to average power. It requires a separate receiver from the transmitting antenna.

Not only that, the sources I have provided indicate this is EXACTLY what's happening in both AWG-9 and the APAR, ie they both have pulse and CW functions in a single system without mention of any auxiliary illuminating systems. In fact, they say that radar functions have nothing more than separate TWT modules dedicated to pulse and to CW. How much do you want to bet that I can find more descriptions of pulse radars with illuminating functions that make absolutely NO mention of any separate illuminating radar systems?

LOL. APAR does not have TWT. Shows you How much you don't know. With AESA you don't need a TWT.

Even if you have a CW illuminator on the same system with a pulse radar, that CW illuminator cannot use the pulse radar's antenna, because the pulse radar's antenna has to be left open for the receive cycle.

Get a grip. You cannot have CW illumination shining out of the same array face that is on the receive cycle and expecting and receiving echoes. Otherwise, go explain how the radar will receive input?

You have been shown to be so flat out wrong about so many things on this topic, including now from this source, that it's now getting ridiculous.

Really?

The only thing here is your slavish belief on non technical sources without truly internalizing the technology and questioning how it truly works.

Explain how you can transmit continuous wave on the same array face that is expecting a receive cycle.

What? "Backend modded" for "testing purposes"? It's clear that you are now desperately grasping for straws here.

I fail to see how interrupting cannot be added to the SPG-69's TWT and backend circuitry.

What a ludicrous attempt at spinning this obvious source. It describes EXACTLY what ICW is by describing how SARH missiles do not need a continuous lighting up of their targets and can receive adequate targetting information by receiving intermittent 'screen shots'. This is just AFTER it describes how mechanically steered CW cannot do this, and just BEFORE it describes how electronically steered ICW does exactly this. If mechanically steered illuminators like the SPG-62 CAN do ICWI, why does this source flatly say they cannot? Why does this source talk about "inertia" as the reason that mechanically steered illuminators cannot do ICWI? If your conception of ICWI as some kind of 'intermediate' between pulse and CW is correct, what does inertia have anything to do with whether a radar can or cannot do ICWI? The answer is NOTHING. NOTHING because ICWI is NOT 'intermediate' between pulse and CW, whatever the hell that means. And again, "inertia" has EVERYTHING to do with ICWI because ICWI requires rapid cycling between several distinct objects in the sky which a mechanically steered illuminator cannot physically do, because of "inertia", the principle that an object moving in a certain direction tends to keep moving in that direction. The micromotions that would be required of the motors on the SPG-62 to nearly simultaneously paint multiple targets is impossible to achieve. That's what this source is saying. Actually you know all this. You are simply refusing to acknowledge the obvious facts that are flying in your face.

First inertia isn't much of a factor with a limited FOV. Ever notice that mechanically slewed fighter radars are still able to track, two, if not up to 4 targets within a cone or band with high PRF?

Did you just ignore where my source said that APAR has separate TWTs dedicated to tracking and illuminating? Not separate radars, separate transmitters, SAME radar, using separate TWT's to track and illuminate, on the same facing PAR panel. There is no pseudo-semi-pulsing simultaneously tracking/illuminating magical beam coming out of the APAR, that exists only in your imagination.

Let me bold out that part of your quote that lets me laughing.

If you actually know what a TWT is, you won't use put it in the same sentence as APAR or any AESA.

Simply said, that sheer ignorance of 101 Basics here does not merit a response on that.

Did you just find out about the concept of FMCW in your Googling or something? Think it will allow you to spin your way out of a losing battle? FMCW is not ICW. There is nothing "interrupted" about FMCW. Is this why you dropped 'frequency' from your post? After all 'modulated' CW to someone who doesn't know does sound kinda like 'interrupted' CW. Do you even know the difference yourself? If so, why even bring up modulated CW?

LOL. FMCW "interrupts" because FM induces a change in the CW.

You friggin don't know what CW is don't you. CW or Continuous Wave is constant. The waveform does not change. Using an audio metaphor that would be like a constant note. When you cause a change in that wave form, that is considered an interruption. Frequency Modulation can be used to create the square or trapezoidal wave forms, much like a pulse. In effect, FM can be used to create that interruption.

time to bring out the Telecom fundamentals.

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"The continuous wave is used principally for radiotelegraphy; that is, for the transmission of short or long pulses of rf energy to form the dots and dashes of the Morse code characters. This type of transmission is sometimes referred to as interrupted continuous wave."

Technically there is something called FMICW. As in Frequency Modulated ICW.

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Frequency-modulated continuous-wave (FMCW) radars offer many advantages such as low peak power, low probability of interception, low interference with other systems, and high-range resolution. However, their major drawback is the isolation required between the transmitter and receiver that typically leads to the use of two separate antennas for transmission and reception. Some schemes have been proposed to enable FMCW radars to operate with a single antenna, such as frequency-modulated interrupted continuous-wave (FMICW) technology. Recently, a stagger procedure has been proposed to overcome the problems associated with the use of the FMICW technique in high-resolution radars. The technique was tested using simulated data. Now, a high-resolution millimeter-wave radar sensor, in Ka-band, has been developed at the Universidad Politecnica de Madrid, Madrid, Spain, to perform an experimental validation of the theoretical approach of the stagger procedure. The sensor transmits a linear frequency-modulated interrupted continuous wave with a maximum bandwidth of 2 GHz and a transmitted power of +29 dBm.

Start reading this carefully, and you might have an actual idea what APAR might be doing.

Down towards the middle of the page:

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I have already told you FAS is a joke.

By the way, ONCE AGAIN you have NO source stating that APAR is not a "true" pulse radar except your own personal opinion. If you understood even the basics of PRF, you wouldn't be saying that.

I'm sorry BUT PULSE RADAR USES ONE ANTENNA FOR SEND AND RECEIVE AND A CW RADAR MUST USE TWO, ONE FOR SEND AND ANOTHER FOR RECEIVE.

You've directly said that they not only have to have distinct circuitry, they in fact have to be two entirely separate radars. And didn't I show you two radars that both emit both pulse and CW?

I'm sorry BUT PULSE RADAR USES ONE ANTENNA AND A CW RADAR MUST USE TWO.

Oops for you. Sorry, NO mention of separate illuminating radars in either of those two radar systems. LOTS of mention of dedicated TWTs in those same radar systems. Oops, oops, oops.

LOL.

You just committed two CAPITAL mistakes in Radar technology. Shows you don't even understand the sheer basics.

1. Illuminating radars.

2. TWTs on an AESA.

BULL. This use of the word modulation is not a technical use of modulation, as in FMCW, no matter how you try to spin this one-liner of a definition. It does say on off keying of a CW. That's EXACTLY what it does to a target.

No.What you're trying to say is that interruption is caused not by the keying in and off

That's EXACTLY what an SARH missile sees as it homes in on that target. FMCW doesn't key ANYTHING on or off. It's a CONTINUOUS wave whose frequency is modulated to provide ranging. NOTHING is being interrupted or being keyed on or off.

LOL. The frequency modulation is used to create a change of state in the wave form. That state of change is used for ranging. For the same reason, the interruptions on CW can be used for the same purpose. An interruption is a change of state. The on and off of an ICW is similar to the send and receive cycle of a pulse radar or the harmonic of an FMCW. In all three, the markers are used to determine range.

You couldn't possibly stretch or spindoctor the definition of either "interrupted" or "on-off keying" to somehow encompass 'frequency modulation of a continuous wave'. On the other hand, like I said, ICWI as I and basically every other description has said, does in fact "key on and off" a target as it cycles between multiple targets. It does in fact "interrupt" its illumination of its assigned targets by illuminating the next target in the cycle. ONCE AGAIN, you are attempting to impart your own misconception of ICWI into this definition.

Once again, you're the expert here. "illuminating radars, snicker, snicker"

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"a novel interrupted, frequency modulated, continuous wave (FMCW) signal waveform. "

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"The paper analyzes the characteristics of cochannel interference (CCI) in the high-frequency (HF) surface wave radar (HFSWR), which adopts the linear frequency modulated interrupted continuous wave (FMICW)."

Hey, a Chinese paper too!

And yet we have a curious statement that a "pulsed continuous wave has a characteristic varied in accordance with the modulating signal". Since according to you, you CAN'T have a pulsing CW, are you now contradicting your own source? How will you spin this one? Nor, and importantly, does it make ANY mention of frequency modulation, an important thing to mention, one would think, as part of a definition of ICW, if in fact ICW = FMCW. Clearly either you're just dead wrong or this source is using words like "pulsed" or "modulation" in ways we aren't, or both. I vote for the last of the three possibilities.

Read the above.

Oh and check Wiki for "Pulse Modulation".

Once again, who says that CW and pulse functions cannot be integrated into a single radar, hardware, software and all?

Sorry, but CW and Pulse can't use the same array face. Oh and please read the papers. Pulse requires circuitry to store up then release to create a high power output.

The peak power of a pulse radar burst is GREATER than the average power being fed into the radar system. This is not true of continuous wave.

Get a grip. Here is the analogy.

Continuous Wave

Water flowing continuously out of the faucet.

Interrupted Continuous Wave.

Water flowing out continuously out of the faucet but someone turning the handle on and off so the water stops and flows.

Pulse Radar

Water flows out of the faucet, collected into a large bucket, then suddenly released.

In fact I've already shown you this is exactly what has happened with these military radars, which have need of both functions in a compact space. Thus the AWG-9 in a single radar has both pulse and CW functions, and the APAR has both pulse and CW functions.

Yeah sure, but calling an illuminator "radar" and saying that APAR has separate TWTs. Snicker.

Please go look up what the hell a TWT is.

You tried to brush off the grossly contradictory AWG-9 source (contradictory for you) by trying to claim WITH ABSOLUTELY ZERO EVIDENCE that there is some kind of separate CW illuminating radar that's not the AWG-9 itself. That's essentially like claiming there is a little genie inside there emitting CW on command. You may get away with making blatantly wrong and unsupported statements in other threads, but not in this one.

Hahaha. If you guessed it by now, that CW is not a radar. Its like a flashlight slaved to the radar.

Please understand what RADAR really means?

Yeah, this is a description of FMCW. So what? Frequency modulation doesn't have any interruptions in it because it's still a continuous wave no matter how you try to spin the word "modulation" to make it sound like "interruption". Your attempt to equate FMCW with ICW is clearly a newly developed front which you coalesced over the last two posts and which you initially did not have knowledge of, or you would have attempted this spin from the very beginning. It's not working.

Please re-educate the IEEE since you know so much better than them.

You know, I don't know why I didn't think of this before. I searched "interrupted continuous wave illumination" using Googlebooks and look at the treasure trove I found.

From Introduction to Electronic Defense Systems By Filippo Neri

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Here is another one:
From Radar Handbook By Merrill Ivan Skolnik

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These constitute yet another TWO additional authoritative source that flatly contradicts your claims about what ICWI is. And yet we have you saying this:

Handbook? Guide?

How the hell they are considered authoritative? For all you know they're written by fans or observers. If you can show me the authors have true EE degrees then you have a point.

Consider that I have shown you are text book information, patent filings, and papers from the IEEE, what kind of weight does a handbook have?

Yes, it in fact DOES work like a lighthouse. BTW, what in the world is an "SPG-69"?

And here's two more sites indicating ICWI is ALL about targeting (multi-target engagement), not what's being emitted (CW).

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Straight from the horse's mouth (Thales):

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[/quote]

LOL. Its marketing information. Like I take information from ads as gospel.

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from overscan.

AI24 Foxhunter Radar

Development

In the early 1960s, RRE (Radar Research Establishment) Great Malvern and Elliott began research into a new type of radar they called FMICW (Frequency Modulated Interrupted Continuous Wave), with possible application in two areas; AI (airborne interception) and AEW (airborne early warning). In a frequency modulated continuous wave (FMCW) radar a continuous wave is smoothly varied in frequency over time. The frequency of received radar signals is then compared with that being currently emitted in the receiver. The combination of the two waveforms gives frequency-triplets which can be decoded to give target range and range rate. However, as radar energy emission is continuous, it needs separate transmit and receive antennas which is not practical in airborne applications.

FMICW complicates this by periodically interrupting the waveform to allow a single antenna to both transmit and receive. This introduces additional complexities to the design over FMCW via PRF intervals and harmonics. However it seemed a method to allow good lookdown detection capability and be a promising alternative to the US AMTI solution used in the E-2C Hawkeye.

In 1963 studies started for a naval AEW aircraft which became the Blackburn P.139. By 1965, FMICW radar technology was looking very promising and the P.139 had settled on an FASS (fore-and-aft scanner system) radar with inverse-cassegrain antennas using FMICW. However, in 1965 the UK carrier fleet was axed and the P.139 consigned to history.

Work continued in Britain on FMICW despite these setbacks. In 1967 a prototype radar flew in a Canberra. A prototype of an FMICW AEW radar was under construction in 1971 but was cancelled on cost grounds, and also because the US was building its new E-3 AWACS with a High PRF Pulse Doppler radar, which worked on slightly different principles to the UK FMICW approach.

By 1967 Britain was formulating the Operation Requirement for the MRCA, and hit upon the idea of an air intercept variant to replace the Phantom in the air defence role. The Tornado ADV (Air Defence Variant) requirement was formulated as long ago as 1969. However, the ADV version was not considered a high priority in the early stages, as the RAF was only just receiving brand new F-4M Phantoms, and a replacement wouldn’t be needed until the early 1980s. Indeed, the contract for AI24 wasn’t signed until 1976, though Marconi had flown test hardware prior to this.

Foxhunter prototype on bench

Marconi-Elliott were given responsibility for developing the AI24 radar for the ADV (incidently, the “Foxhunter” name was never official; the designation for the radar was just AI24) with Ferranti supplying some components. Requirements for AI24 were ambitious. ADV was expected to intercept Soviet bombers and cruise missiles at extended distances, at high and low altitudes. Detection range for a typical bomber was to exceed 100 nautical miles (185km) and the radar was expected to track multiple targets simultaneously. Emphasis was placed on ECCM capabilities as the intended targets were assumed to use powerful ECM systems. Lookdown detection ranges were expected to be as great as possible.

In order to meet these tough requirements, Marconi-Elliott decided to base AI 24 on their longstanding work on FMICW radars, which had seemed to offer strong lookdown performance and long range detection, and, crucially, was thought to offer good resistance to ECM.

The US meanwhile had moved on from AMTI to modern pulse-Doppler radars. The F-14’s AWG-9 was a High PRF pulse Doppler radar with FM ranging for long range target detection. Marconi’s own FMICW concept was largely a version of the same concept, the distinguishing features of FMICW being extremely high PRFs, very high duty cycle (near 50%), and the use of a single range gate; that is, rather than dividing the interpulse receiving period into individual range cells corresponding to targets at different ranges and analysing them separately, a single sample was taken of the whole interpulse region. This integrated the returns (and hence clutter) from many range cells into a single range gate. The magnitude of the ground clutter is therefore typically high, 80-90dB above thermal noise, requiring an exceptionally good dynamic range signal processing chain, extremely low sidelobe levels and a very pure transmitted signal to allow successful target detection. However, it simplified the processing as only a single set of Doppler filters needed to be formed, rather than multiple filters for each range gate. Early FMICW radars used analogue processing; for AI24 Marconi used digital signal processing.

A fibreglass based, twist-cassegrain antenna was selected, for two main reasons. Firstly, very low sidelobe levels were thought to achievable, which helped in ECM resistance and was also important as outlined above for FMICW performance. Additionally, the resulting antenna was extremely lightweight (just 3lb!), which reduced inertia and allowed rapid scanning, which would be helpful in track-while-scan mode."

Oh now, you are starting to get the picture. Basically by using ICW, you can use the same antenna as both send and receive. Oh and please note, its not even using an AESA but an old type mechanical antenna.

This does not mean you can put Pulse and ICW on the same antenna. The emission of both has to be synchronous, resulting in the pulse and ICW emission interfering with each other, and during the receive side, reading both ICW and pulse echo will create ambiguous readings. An array face, even with AESA has to be governed by a single clock in order to be synchronous. The pulse radar and the ICW has to be of the same frequency and PRF. So what's the point? You only need one modal type to do everything. Please note that PRF harmonics are applicable to ICW.

You have to take one radar operating model that can simultaneously do all these

1. Target tracking and ranging.
2. Single Array face
3. Target illumination

You don't have much models left.

If APAR is an AESA Pulse, adding a separate CW transmitter inside the array face is kludge, and a bad one. Why don't you just put the CW transmitter separately like with other systems? The AWG-9 has space constraints. A ship doesn't. Putting both together interferes but you don't have much choice in the constraints of a fighter which is why the AWG-9 cannot be used as an example on this. Note how far the SPG illuminators on the AEGIS is from the SPY-1 panels.

So you tell me why you would put the CW illuminator inside your purported APAR "pulse" radar.

Now lets say, since APAR is an AESA, on the same target, why would you need a separate beam for pulse using an X number of elements for ranging and tracking, and then use another set of X number of elements for CW illumination? That seems horribly inefficient.

Why don't you just use the same beam with the same set of elements on the same target to track, range and illuminate at the same time? By doing so, doubles either the energy used on the targets, or double the number of targets you can track and illuminate.

It just seems to me, you can't get your brains around your "bibles", figure out technical implausibilities and work out plausible and elegant technological solutions.

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Radar, sonar and other modern military sensors

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