SinoDefence Forum

bd popeye

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.

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"I am what I am.... 'Dat's all what I am"

crobato

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.

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.


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.


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?

Radar systems analysis and design ... - Google Books


And you far less.



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


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?

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.

Definition: interrupted continuous wave

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.


US PATENT SUBCLASS 329*/*311-- PULSE OR INTERRUPTED CONTINUOUS WAVE DEMODULATOR


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.

http://www.bbc.co.uk/dna/h2g2/A743807

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. "

__________________
"Lets do a thermal sweep."

Wolverine

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.

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.


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:

Pulse repetition frequency - Wikipedia, the free encyclopedia

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.

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.


LOL

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?

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

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.

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.

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:
Continuous Wave Radar

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.

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.

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.

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

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.

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
Introduction to Electronic Defense ... - Google Books

Here is another one:
From Radar Handbook By Merrill Ivan Skolnik
Radar handbook - Google Books

These constitute yet another TWO additional authoritative source that flatly contradicts your claims about what ICWI is. And yet we have you saying this:
And this:
And this:
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).
http://www.armadainternational.com/04-1/digest.cfm

Straight from the horse's mouth (Thales):
http://www.thales-nederland.nl/nl/ne...l08-2005.shtml

Wolverine

Redundant post (merged into previous post).

crobato

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.

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.


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.

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.

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.

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.


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?

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.

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

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?

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.


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.

Introduction to communications theory

"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.

Welcome to IEEE Xplore 2.0: Millimeter-Wave Sensor With FMICW Capabilities for Medium-Range High-Resolution Radars

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.

I have already told you FAS is a joke.

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.

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

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.


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


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

US 5673050 - Three-dimensional underground imaging radar system

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

Welcome to IEEE Xplore 2.0: Adaptive cochannel interference suppression based on subarrays for HFSWR

"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!


Read the above.

Oh and check Wiki for "Pulse Modulation".



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.

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.

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?

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.

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?





[/quote]

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

Tornado ADV (F2/F3) Avionics

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.

Defense ad material is not obligated to tell the whole functioning truth. They only need to sell and even have a purpose to mislead from potential opponents.

__________________
"Lets do a thermal sweep."

Wolverine

You have a habit of brushing off people who wrote books that flatly contradict your claims as idiots and as people who don't know what you know. What the hell do you know anyway? And who the hell are you compared to people who write books on the subject? A self-styled internet expert who can't tell the difference between a TWT and an illuminator (which completely destroys any remaining credibility you may have had), who has no idea what PRF or FMCW really means, and who who doesn't have the first clue what ICWI is especially when five different sources say the same thing, oh, which happens to DIRECTLY contradict your claims about ICWI.

Have you become so clueless as to now try and equate a TWT as an CW illuminator? Do you even have the first clue what a TWT is? Or is this the extent to which you must now spindoctor your egregiously and ridiculously erroneous claim that pulse and CW can't happen in the same radar, in order to have your fantasies be shoehorned into any semblance of reality? You actually didn't even have to know that a TWT is not an illuminator just by simply reading the description of TWT in the AWG-9 page, or even just by reading the description of a TWT in Wiki or by Google. But you didn't even bother to do that before you mindlessly shot off yet another bizarrely surreal post making yet another brand new foray into Lala-land. How can you reconcile your claim that TWT = CW illuminator when the AWG-9 also devotes a TWT to pulse? How can you reconcile your claim to the fact that the SPY-1 and other radars use TWT's? SPY-1 has NO illumination function at all. NONE. Your posts are getting more and more surreal as you depart further and further from reality because each pseudofact that you put out has to be covered in the next post by an even more surreal pseudofact. It's a house built on sand.

CPI Wins $4.9 Million Military Contract

TWT is nothing more than an RF source (like the earlier magnetrons and klystrons) which is then amplied and channeled into the next step in the radar emissions process. A TWT can be used to supply either pulse OR CW emissions. Hence, the AWG-9 has two TWT's, one for illumination, one for pulse emission. Note that the AWG-9 is still one radar, the same radar that emits either pulse or CW, the same radar that has TWS capability even as it guides Sparrows with its CW function. Your futile and illogical attempt to equate TWT with CW illuminator utterly fails. Your futile and illogical attempt to claim that pulse and CW cannot be emitted from the same radar utterly fails because only in some queer other reality does TWT = CW illuminator. Here, educate yourself:

Traveling-wave tube - Wikipedia, the free encyclopedia

So are you saying that the Naval Institute Guide claims that APAR has an infinite PRF? What a joke. What a hideous spindoctoring of reality. Once again, PRF is only a factor in pulse radars. Like the APAR. Which is why the book talks about PRF in the APAR section. The logic is clear to the average person. The reason it's not clear to you is simply because you refuse to acknowledge truth staring you in the face, all for the sake of pride, all for the sake of not wanting to admit you're wrong, and wrong about so many of these things.

Oh really? So according to this definition, what's the difference between "pulse" and "ICW"? Thrill me with your acumen.

It really doesn't matter what you say about this issue at this point. It's clear that radars can integrate the hardware and software of pulse and CW into a single radar system. The problem in understanding lies with you.

Here is Ambie's source again, this time in reference to pulse (TWS) + CW (semi-active illumination) in the same radar. Man, the evidence against your queer claims sure do add up, don't they?

This is the same principle that all aircraft-mounted planar array radars used prior to the advent of ESA's.

Get a clue. The same array can shift from CW to pulse back to CW nearly instantaneously, depending on what target it's shining on. It can do CW for a few microseconds on an incoming missile, then shift to tracking a friendly AWACS in the next few microseconds, then shift to CW on a second incoming missile for the next few microseconds, and so on and so on. And that's just for a PESA. It's actually very similar for a planar array. An AESA like APAR can do the same task simultaneously by subgrouping different T/R elements into tracking (pulse) or illuminating (CW) subgroups. The tracking elements which need to receive can still receive, and the illuminating elements which don't need to receive, won't. I believe I have already mentioned this exact capability in an earlier post. It seems you don't understand the basic principles of ESA's, or you have a poor memory.

What a ludicrous statement coming from you. The two books I quoted that flatly contradicted you are BOOKS, not some non-technical internet fanboy sources: "Introduction to Electronic Defense Systems" and "Radar Handbook". And frankly, compared to you (or I), any book is a technical source. Just leafing through these books it's obvious they know more about radar systems now than you personally will ever learn in your lifetime. And make no mistake they directly and blatantly contradict your claims about what ICWI really means. You don't have the right to unceremoniously brush off these authors just because they happen to completely trash your surreal claims and expose them for what they are. That's pride talking. That's ego in the face of cold hard reality smashing down your house of sand.

I just did. You don't emit CW and expect a receive cycle at the same time. You don't have to. Understand?

First, typical planar array radars on fighters emit in a much wider potential cone than the pencil-beam emitting radars on surface ships, ala SPG-62. What an AWG-9 can cover is probably orders of magnitude more than what an SPG-62 can do. Planar array beams are also electronically steered to an extent. An SPG-62 has no dimension which is electronically steered. There is not even a comparison to be made here. But all this does absolutely NOTHING to mitigate the fact that the source directly states mechanically steered illuminators (like those used on SHIPS) cannot do ICWI because of inertia, and why ESA's CAN do ICWI because they're electronically scanned. We both know exactly what the author means by this. ICWI is a means of multitarget illumination, not a certain type of RF emission. My other two book sources confirm exactly this. Thales itself confirms this. Your misunderstanding and/or misrepresentation of your own sources can do absolutely nothing to cover this up.

Second, there is no such thing as an SPG-69.

Third, "backending" an SPG-62 to "interrupt" a CW illuminator makes it a pulsing illuminator, not an ICW illuminator.

Laugh all you want, you're the one who thinks that a TWT is an illuminator.

All this is your grand attempt to equate ICWI with FMCW and now FMICW because it contains the word "interrupted". Fact is, FMCW does not equal ICWI and FMICW does not equal ICWI no matter how you spin these sources. They are completely different concepts. Just the name themselves testify against you. Why call something FMICW when you can just call it ICW? Why call something FMCW when you can call it ICW? And neither of these concepts and neither of your sources refer to their application in illumination of multiple targets, as is Thales claim for what ICWI does. Clearly until these latest posts you didn't think they were the same thing. Or at least you didn't try to front like they were the same thing. Here is what you said before:
Clearly you believed that FMCW and ICW were distinct entities until you decided you had to try and fudge them into the same thing.

You want to know what's a joke? Here, this one's the real joke:
I believe you could do well in Washington as a political pundit. Over there they all know how to spin like a friggin top. Fact is you still can't decide whether you want this hypothetical beam to be continuous, or interrupted, or frequency modulated, or pulsed, or whatever the hell you dream up next. You're trying desperately to conflate ALL of these together into the same thing in the vain hope that somehow some way people will get mixed up in all these terms and forget that you have no idea WTF you're talking about and that you're just throwing out terms there with no understanding of them at all.

"CW radar"? Didn't you get all arrogant about illuminators not "technically" being radars? Aren't we talking about the illumination capability on APAR and AWG-9 here? Didn't you specifically call AWG-9's a "CW illuminator"? So how the hell is it a radar all of a sudden? Try not to sound so uppity next time when you are guilty of the same thing you accuse someone else of. That's called hypocrisy.

For someone who has no idea WTF a TWT even is, I wouldn't be laughing. Actually the correct term on an AESA is "waveform generator" which I lazily called a TWT. They are not technically the same, but the principle of generating and amplifying a RF source is the same. And make no mistake, the APAR has separate waveform generators dedicated to tracking and illuminating. This is confirmed both by the Naval Institute Guide and this source:

LCF Frigate information page

Oh, so ICW is "similar" to FMCW or pulse? How similar? In all your spindoctoring you've tried separately to directly EQUATE ICW with either FMCW or pulse by alternately claiming that ICW is somehow "interrupted" in pulse fashion or "modulated" in FM fashion. Well why don't you finally make up your mind and spindoctor the final version for me?

And this means what? Nothing but another ham-handed attempt to seize upon FMICW in your attempt to cloud the fact that besides the common word "interrupted" there is nothing here for you to spin together to get from FMICW to ICWI. Your ramblings above clearly indicate you understand neither FMICW nor FMCW nor pulse nor, more importantly, how to best use them to make ICWI mean what you want it to mean.

LOL. I like the part where you try so hard to distinguish ICW from pulse here. A bucket eh? Actually, "bucketing" is not a necessary part of the definition of a pulsing radar. The only necessary defining aspect of a pulse radar is that the handle be turned on and off, so no matter how hard you try to spin this little "analogy", it's not going to work. If you are trying to spin that pulsed radars "need" stuff like pulse compression to be defined as pulsed radars, you're just wrong. Even if you were right, the lack of such augmentation on an alleged "ICW beam" just means it would be a substandard alternative to pulsed radars. You might as well use a straight up pulsed beam to both track and illuminate. Fact is, even after all this spinning you still can't make a case for the existence of an "ICW beam", or just as importantly, why it should even exist as a viable alternative to a pulse beam as a means of illumination. Fact is, there is no "ICW beam". ICWI is as ALL of my relevant sources describe, a means of using a single radar to illuminate multiple enemy targets by time-sharing a CW beam among them.

Hahahahahahahahaha

I see. An internet fanboy, someone like you, wrote an entire book called "Introduction to Electronic Defense Systems". If you were actually capable of writing such a book, I actually would give you some respect. But we both know better, don't we? No, the guy who wrote that book has more creds than you will ever have, you and all your egregrious misinterpretation/misrepresentation of those "IEEE" sources you posted.

OMG that's so pathetic. So you're claiming that Thales is somehow lying or exaggerating when it claims that ICWI is "a technology that enables a missile control system to guide several missiles simultaneously to various threats"? So, what exactly is it lying or exaggerating about here? That ICWI is NOT such a technology? That it is actually an in-between-pulse-and-CW-pseudo-pulsed-modulated-mumbo-jumbo beam that only you are aware of? Is it a conspiracy they are trying to cover up about the true nature of ICWI? What exactly are they not being entirely truthful about here in this statement? Please, do tell. Actually, don't bother. I have no need to read another hideous attempt to spindoctor away yet another source which flat out unambiguously contradicts your ideas of ICWI.

OMFG please tell me you did NOT just sink to new desperate lows and link some post from another forum as a piece of evidence. That just takes the cake. I actually came across several forum sources which say the exact same thing I've been saying about ICWI but they were beneath my intellectual dignity to post as evidence here, as I see them as no better qualified than yourself. Or myself, for that matter. I guess you have no such qualms posting other internet fanboy's opinions here and treating them as gospel. Good for you. LOL

What the hell are you talking about? There is no separate ILLUMINATOR inside either the APAR or the AWG-9. The TWT is NOT an illuminator for cryin out loud. You know that I know that you know that you have to front that a TWT is an actual illuminator when it is in fact no such thing. And YOU were the one who so arrogantly acted all uppity when telling me I didn't know what a TWT was. We both know the reason that you have to claim that the TWT is an illuminator is to support your thesis that you can't have both pulse and CW in the same radar. Yet how can your queer thesis hold up if my source states that the AWG-9 has a separate TWT for pulse and one for CW? Why, easy! Claim that a TWT is somehow actually an "illuminator", and presto! Two distinct machines in the same nosecone. How pathetic. A TWT module lies on the back end of a radar set, like it does for an AWG-9. Like it does for a (non-illuminating) SPY-1 panel. Oops, forgot about the SPY-1? Need that source again that I posted above? How can TWT be an illuminator if SPY-1 doesn't illuminate? Why would a SPY-1 need a "TWT illuminator" (actually several of them behind each PAR face) if it's already got several SPG-62 slaves handy? A TWT is not a separate entity. It's an integral part of a radar system. No TWT, no emission of ANY kind, CW or pulse. So let's drop this idiotic pretense you're fronting here. It's just got too many holes for you to successfully spindoctor into a viable pseudofact.

Who cares what it seems like to you personally? With AESA's you can either 'permanently' assign a subgroup to either tracking or illumination, or to both by time-sharing. With a PESA like the PAC-2 radar (with only a single TWT), the entire panel does both, by time-sharing. Like I said before, the PAC-3 has two TWT's, which then allows the radar to start assigning different elements to different jobs. One to track (pulse), one to illuminate (CW), or both to track, etc.

Probably because SM-2 and ESSM can (so far) only handle CWI and ICWI. They would probably have to have additional hardware and/or software modification to learn how to read simultaneously interrupted AND pulsed illumination. At least with ICWI, when it's on target, it's on 100% of the time. Add a pulsed illumination to the time sharing and you will end up with even less illuminated time than a missile had to go by with CWI. Some day some missile may achieve this, but today is not that day.

Pffft.

That is so pathetic. So basically every source that disagrees with you is either unqualified compared to you or has some motive to hide a conspiracy about the ICWI. As far as I'm concerned you're utterly finished. I've got sources that would satisfy a man of honesty and unbiased neutrality. Two people who wrote books on radar, Thales itself, and two additional independent sources which totally corroborate the statements made by the books and by Thales. WTF do you have? Nothing that directly counters any of those sources. What you do have are a couple of websites the contents of which you don't even fully understand and which you have been completely unable to assemble into a coherent spindoctored version of what you would like ICWI to be. By any unbiased measure, you do not have the truth on your side.

Oh, and by the way, I just looked up the credentials for the author of Introduction to Electronic Defense Systems, on page 599. You can view it through the same link I provided earlier. Just scroll down. You are ABSOLUTELY finished, as he represents the highest and most relevant knowledge bank for this discussion. PhD in electronics engineering from Rome University, became head of the Tracking Radar Department of Marconi Systems, then Electronic Warfare systems manager, written many technical articles, holds many international patents, bla bla bla. Hardly an internet fanboy like yourself, wouldn't you say? This guy could take a warm dump on all those IEEE websites. Just scroll through his book, and you'll see for yourself.

bd popeye

Enough Wolverine. Enough. I've sent you PMs asking you to tone it down. Deleted post etc.. I cut you some slack because you seem to be rather intelligent.

Personal attacks and insults are not allowed in our frorm. Go elsewhere and spew you argumentative ways. You are banned.

Other members feel free to discuss Radar, sonar and other modern military sensors as you wish

bd popeye super moderator

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crobato

Very funny. a TWT stands for Traveling Wave Tube. If you have any idea what a TWT looks like in the first place, you won't mistake it for being part of an AESA element.

It is part of an illuminator for crying out loud. TWTs are used on illuminator as they are on radars.

Traveling-wave tube - Wikipedia, the free encyclopedia

Also, SPY-1 has one TWT. Radars may have multiple emitting horns, but unless you are an AESA, you only have one wave form generator.

Since Wolverine much of your replies are pure garbage and you are justly banned, I like to clarify and inform to the rest of the members of the forum how the systems do work.

Pulse Radar:

Has a Send-Receive Cycle. That means it shouts, then listens, shouts and listens for the echo.

Single antenna. Which means it divides the antenna usage time which it sends and receives. The antenna has a dual purpose.

Burst. When the radar is on a receive part of the cycle, it still is receiving constant power from its power source. It takes that constant power and stores it. That power is then unleashed in a powerful burst. The resulting peak power is much higher than the average power the radar set receives from its power source. Already the circuitry used for pulse radar is more complex than a CW one, but the resulting power gives pulse radar much greater range, albeit also makes it more easily detectable.

Continuous Wave

Sends a continuous signal, like a constant note. Since the sending antenna is always sending, it requires a separate receiving antenna. The duty cycle, unlike the pulse radar, is 100% send in one antenna, 100% receive on the other antenna.

CW doesn't store up power and send it in bursts. Thus it lacks high power peaks. This makes the radar less detectable but also less range. Circuitry is simpler.

Why you can't mix CW on a pulse radar set? It's too obvious. Both cannot share the same antenna and circuitry. A CW requires two antennas and 100% duty cycle on both, while a pulse radar has a single dual role antenna that divides its duty time between send and receive.

Interrupted CW takes the CW and divides it into send-receive cycles so you have a single antenna. This creates the conditions of a pulse during the send part. Except that ICW lacks the peak power of a true pulse radar and the underlying circuitry is still not the same. For discussion purposes, people refer to the send duty part of the ICW as a pulse, because that is what functionally it does, except for the high peak power part. Because it has a send-receive duty cycle, PRF also applies to ICW; the longer the cycle, the longer the range.

But still you cannot share ICW with true Pulse on the same array face. You would have to synchronize ICW duty cycles with the Pulse duty cycles, and when emitting ICW during the same send period of the Pulse, the Pulse is going to be a lot more powerful.

At the same time, the radar set will be receiving two echoes simultaneously during the receive period from the target, both the pulse signal and the ICW. Interference and ambiguity.

Do note that if the ICW has to illuminate the target, the Pulse radar still has to track that target and therefore has its own radio waves shining on the target as well. Otherwise, the ICW won't know where and who to illuminate. The illuminator is slaved to the tracking radar.

Therefore if you only one set, that needs to accomplish detection, tracking, ranging and illumination, you would need either a modulated CW set or a pulse radar with an extremely high PRF such as the PRF would appear to have a continuous harmonic. Under modulated CW sets, you can have FMCW, ICW and FMICW. In ICW, you should be able to use the rise of the wave for ranging. To tell range, ICW and Pulse radars shouldn't be different. FMICW comes in when the interruptions of the CW are not used for range purposes, but only to create send-receive duty cycles on a single antenna. The FM is used to create markers on the CW which is used for ranging.

You tell range based on the time how long it takes for the wave to travel from origin to source, then factor the speed of light. Its easy on a pulse, but not in a set where you are continually receiving. Thus, you modulate markers into the wave and measure the time when the marker returns to you. PRF theory can also apply here on the markers; longer PRF is needed for longer ranges, and the set has to wait till it receives the echoed marker before it modulates a new marker into the emitting continuous wave.

Since RADAR is RAdio Detection And Ranging, CW itself cannot be considered radar, for the least CW to be considered a radar, it has to start with Frequency Modulated CW at least.

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Ambivalent

As I understand ICWI in USN service, individual missiles have a frequency oscillator built into the homing system that causes the radar to home only on the reference frequency. Missiles in flight will have different reference freqs they will home on. The illuminator will change carrier freqs during illumination, allowing more than one missile to receive guidance information from a single illuminator. It is not an issue of pulsing the signal. Illumination is continuous, but the freq changes.
Btw, the beam from an illuminator is not this thin pencil beam oft claimed, but is a narrow ellipse. At it's widest point, this elliptical beam can capture more than one target if the targets are close, as might be the case in a saturation attack. Keep in mind by saturation attack I mean hundreds of inbound targets all at once, the nightmare scenario the USN faced in a war at sea with the VMF.
Also, ask why, if ICWI is confined to APAR radars, the capability was developed for SM-2 in the 1980's, long before the appearance of APAR's at sea.

Engineer

So what? At any instance every target within the beam will still be illuminated by the same frequency, as opposed to each target being illuminated by completely different frequency. These are two different concepts.

No. The beam is not elliptical. You are confusing beam "shape" from a plot of the antenna's gain. People say "pencil beam" not because the beam has a physical shape like a pencil, but because the angular range where the antenna's gain is higher than -3dB is extremely narrow.

Here is an example of such a plot:
http://www.df9cy.de/tech-mat/cy432-9...2h-el-plot.jpg

The purple lines shows the FOV with gain higher than -3dB. The performance of an antenna is measured relative to this -3dB value. Nobody cares about that "widest point". Beamwidth, without mentioning of -3dB, would be the angle defined by the sharp end of that tear drop shape, in the case of this example, it is 18.2 degrees. It means you are not going to get jack when the object is offset 18.2 degrees from the boresight axis, NOT getting everything within a 18.2 FOV.

Either the SPG-62 has a pencil beam, or it doesn't. It can't have a pencil beam while seeing everything within a 6 degree FOV at higher than -3dB at the same time.

This said nothing regarding a mechanical radar's ability to achieve ICWI. If APAR on land achieved ICWI, then that still says ICWI is achieved before the appearance of APAR's at sea.

But assuming that you and crobato are correct for the moment. Using your logic, every single mechanical illuminator out there would then be able to achieve ICWI by cycling through different frequencies. Since everyone can do it, ICWI doesn't sound all that special then.

Ambivalent

ICWI depends a lot on the geometry of the engagement, does it not. You have to have targets aligned with the beam from the illuminator for this to work, and that will only happen in a stream raid. Then again, this is the reason the capability was developed. It went to sea with SM-2 Block IIIA. Block IIIB deleted this capability to make way for an IR sensor. There are unfulfilled plans to make yet another block with both ICWI and IR capability, but the push now is for active radar homing, Block VI. This will hit the fleet in two years.
Like cluster munitions, active radar guided missiles ( Bat ) which were developed way back in WWII, ICWI came into service a lot earlier than most people are aware of.

crobato

More than one target cannot be illuminated by the same frequency. The homing system will be confused because it wil lbe receiving two different echoes. The valid target would have to be the one with the strongest signal, and the weaker one will only be interference. It has to stay with one target per frequency.

From what I understand, the final leg of travel of the missile to the impact point has to be illuminated. The closer the missile is to the target, the higher the priority of illumination. Those that are closest to the target has to be a must till the target is prosecuted or missed. The rate of time sharing isn't constant among different targets, but varies in priority, with the closest one to the target an absolute must.

Now whether all these things need to happen very fast that's the question. There is a requisite dwell time for every missile seeker to successfully lock in. You can't or shouldn't switch targets faster than the minimum dwell time.

ICWI isn't that special, concept is already being tested even before the seventies for different reasons, one of which like I said, time sharing of send and receive periods in the same antenna. But basically ICW is also part of basic radio telecommunications, you can communicate through it with the interruptions and periods, like making an SOS signal via Morse Code.

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Engineer

So you are trying to tell me that all the targets will all be within the pencil beam? That's not likely to happen as pencil beam really has an extremely low FOV but for arguments' sake lets assume it does. Does ICWI work here? No! Because at any instance, each target still receives the same frequency. You switch to one frequency and all of them are being illuminated. You switch to a second frequency and all of them are still being illuminated. As I have mentioned in my previous post, this is different from the concept of painting each target with a different frequency.

Take a flash light and shine it on three ping-pong balls. Put a red filter in front of the flash light and all the ping-pong balls will be red. Use a blue filter and all the the ping-pong balls will be blue. Use a green filter and all the ping-pong balls will be green. Sure, you are switching frequency, but you are still lighting up three balls at once.


Which has absolutely no relevance to the discussion at hand.

Engineer

Exactly. If multiple targets got into one beam, then there will be multiple reflections. Yet, this is what Ambivalent is claiming to allow SPG-62 to achieve ICWI.

Of course.

And for a mechanical radar, the only way to achieve anything close to ICWI is to physically steered the antenna at those individual targets. Using one beam to encompass all the targets and thinking it is ICWI is a pipe dream.

So you would agree that other mechanical illuminators could also perform ICWI?

crobato

No, the TWTs will have to be each on separate array on the same panel. This whole description has no grasp on the basic concept of send-receive cycles.

An array on a send period cannot receive and when it is on receive, cannot send.

You don't time share pulse and CW in the same array because you are already time sharing Send and Receive.

AESA can assign a section of elements for send, and another section for receive.

Another thing, an array, even an AESA, works from a single synchronous clock oscillator. Timing of pulse radar and continuous wave aren't synchronous.

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