LM/USN RE-DESIGNATE LRDR AS AN/SPY 7 (V) 1

[DAVID DUNLOP]

LRDR

I thought this was a well written article explaining the physics and cost behind the decision for S band vs X band in the LRDR (now SPY-7) radar.
The bottom line was to get the same sensitivity from X band as S band requires twice the number of transmit/receive modules. The advantage of X band is better discrimination, but the improvement was not considered good enough to justify the higher cost.

Interesting article BJS., A very technical article however, only one mans opinion. Perhaps S Band isn't as superior than we are led to believe vs X Band. The big question is power and cooling. How much of it would have to be generated on the CSC IOT get the discrimination required. If you have seen a true X Band radar, it is the size of an oil platform! The SPY 6 (V) 1 Dual X & S Band AMDR seems to a better fit now however a bit too big for the CSC mast I believe (more expensive too). Cheers!

 

[Calculus]

LRDR

I thought this was a well written article explaining the physics and cost behind the decision for S band vs X band in the LRDR (now SPY-7) radar.
The bottom line was to get the same sensitivity from X band as S band requires twice the number of transmit/receive modules. The advantage of X band is better discrimination, but the improvement was not considered good enough to justify the higher cost.

S-band is kind of the jack-of-all-trades band, if you wish. It is a good long range search radar, but also offers enough "discrimination" to track for fire control at a greater distance than X-band. Typically, however, there is a hand over to a dedicated X-band radar (with better image resolution/discrimination) at some point in an active intercept scenario. The infographic below shows the difference in frequencies between bands (source IEEE).
Basically, rule-of-thumb, the higher the frequency, the shorter the wavelength, the shorter the range - but the better the radar return (or image). So, all things being equal, S-band (which is at a lower frequency, and longer wavelength) will get returns from further way than X-band, but the resolution of the imagery will be less than with X-band. You can overcome the X-band range limitation with more power (as pointed out by the author in @Black Jack Shellac's post) but the cost to do so increases dramatically. Thus the compromise combination of both an S-band radar (mostly for volume search), and X-band (for tracking and targeting) on most major naval warships. Another note, however, is that S-band discrimination is not as much of a real-life issue anymore, as the computing power and associated software algorithms can compensate for the lack of discrimination, to a large extent. Of further note, the Australian CEAFAR2 radar array operates in the L-band (as well as S and X), and should be able to detect objects at an even further range than a typical S-band radar.

A good (though simplistic) analogy can be had with WiFi. WiFi typically operates at two different frequencies - 2.4 and 5.0 GHz. Anyone with a modern router that supports both will be able to attest to the fact that at the same power levels you will be able to connect to the 2.4GHz band from further away than the 5.0 GHz, but the 5.0 GHz band will be faster (more bandwidth). In this analogy, the 2.4GHz would be S-band (longer distance/slower speed), and the 5.0 would be X-band (shorter distance/faster speed). Note that speed in this analogy is information. More speed is more information. Speed/information is greater the higher the frequency. Range (distance) is shorter at the higher frequencies.

 

[DAVID DUNLOP]

S-band is kind of the jack-of-all-trades band, if you wish. It is a good long range search radar, but also offers enough "discrimination" to track for fire control at a greater distance than X-band. Typically, however, there is a hand over to a dedicated X-band radar (with better image resolution/discrimination) at some point in an active intercept scenario. The infographic below shows the difference in frequencies well (source IEEE).
Basically, rule-of-thumb, the higher the frequency, the shorter the wavelength, the shorter the range - but the better the radar return (or image). So, all things being equal, S-band (which is at a lower frequency, and longer wavelength) will get returns from further way than X-band, but the resolution of the imagery will be less than with X-band. You can overcome the X-band range limitation with more power (as pointed out by the author in @Black Jack Shellac's post) but the cost to do so increases dramatically. Thus the compromise combination of both an S-band radar (mostly for volume search), and X-band (for tracking and targeting) on most major naval warships. Another note, however, is that S-band discrimination is not as much of a real-life issue anymore, as the computing power and associated software algorithms can compensate for the lack of discrimination, to a large extent.

A good (though simplistic) analogy can be had with WiFi. WiFi typically operates at two different frequencies - 2.4 and 5.0 GHz. Anyone with a modern router that supports both will be able to attest to the fact that at the same power levels you will be able to connect to the 2.4GHz band from further away than the 5.0 GHz, but the 5.0 GHz band will be faster (more bandwidth). In this analogy, the 2.4GHz would be S-band (further distance/slower speed), and the 5.0 would be X-band (shorter distance/faster speed. Faster speed because more information can be transferred at the higher frequencies).
Excellent summation on S Band LRDR vs X Band SSR comparisons Calculus! Cheers!

View attachment 47085

 

[DAVID DUNLOP]

Very good summation on S Band LRDR vs X Band SSR Radar technology and their strengths/weaknesses Calculus! Still not sure however, where this leaves Canada WRT the "other" radar on the CSC Frigate mast, but hopefully both MDA & Lockheed Martin will let us all know soon enough. Cheers!

 

[Black Jack Shellac]

I was doing some more digging on the mostly missile defense website and found couple of other interesting articles that are related to the LRDR (now SPY-7)

Estimating the Range of LRDR
New Aegis Radar to be 100 Times More Sensitive than Current Radar

Taking these two articles together I thought it would be interesting to do a back of the envelope calc on the sensitivity of the radar proposed for the CSC. Previously we estimated the face area of the radar to be ~ 5.76 m^2 (see post 2139 on RCN thread). Using the math provided in the first article, I get an estimate of 1.23 times the range of the SPY-1 radar. However, the second article describes how the SPY-6 is actually 100x more sensitive than SPY-1, not 30 times as originally planned. It would then follow on that the radar would be 1.64 times that of the SPY-1.

On another note, the discussion of frequency had me thinking about the opacity of the earths atmosphere.

Source NASA - public domain - image from wikimedia

Further info on atmospheric attenuation

Looking at the image, the atmosphere starts becoming opaque at around 2 to 3 cm, or right at the upper edge of the X-band. This would suggest that as you go to higher frequencies, you also lose range due to atmospheric interference. At the lower end, it is near the middle of the HF-band. So useful radars for long range need to be in those bands that fall between. My understanding is that stealth technology is also less effective at lower frequencies (please correct me if I am wrong - I know it is far more complicated than just frequency).

So picking a frequency becomes a total compromise. Higher frequencies give better resolution and more accurate range since the wave length is shorter, but don't have the range due to atmosphere and are not as capable against stealth. Lower frequencies give better range but are not as capable for targeting.

I think the choice of S band is a reasonable compromise.

 

[Calculus]

I was doing some more digging on the mostly missile defense website and found couple of other interesting articles that are related to the LRDR (now SPY-7)

Estimating the Range of LRDR
New Aegis Radar to be 100 Times More Sensitive than Current Radar

Taking these two articles together I thought it would be interesting to do a back of the envelope calc on the sensitivity of the radar proposed for the CSC. Previously we estimated the face area of the radar to be ~ 5.76 m^2 (see post 2139 on RCN thread). Using the math provided in the first article, I get an estimate of 1.23 times the range of the SPY-1 radar. However, the second article describes how the SPY-6 is actually 100x more sensitive than SPY-1, not 30 times as originally planned. It would then follow on that the radar would be 1.64 times that of the SPY-1.

On another note, the discussion of frequency had me thinking about the opacity of the earths atmosphere.

Source NASA - public domain - image from wikimedia

Further info on atmospheric attenuation

Looking at the image, the atmosphere starts becoming opaque at around 2 to 3 cm, or right at the upper edge of the X-band. This would suggest that as you go to higher frequencies, you also lose range due to atmospheric interference. At the lower end, it is near the middle of the HF-band. So useful radars for long range need to be in those bands that fall between. My understanding is that stealth technology is also less effective at lower frequencies (please correct me if I am wrong - I know it is far more complicated than just frequency).

So picking a frequency becomes a total compromise. Higher frequencies give better resolution and more accurate range since the wave length is shorter, but don't have the range due to atmosphere and are not as capable against stealth. Lower frequencies give better range but are not as capable for targeting.

I think the choice of S band is a reasonable compromise.

Great post Jack. I agree with your conclusion. SPY-7 looks like a very worthy radar for CSC. 1.64 times the detection range of SPY-1 on what is ostensibly a GP frigate is pretty darn good. And given this is derived from the Long Range Discrimination Radar (emphasis on "discrimination"), I think it is safe to say that LM has employed some technology and software trickery to reduce the resolution difference between it and a dedicated X-band radar to possibly very little, if any.

 

[ASSAIL]

Great post Jack. I agree with your conclusion. SPY-7 looks like a very worthy radar for CSC. 1.64 times the detection range of SPY-1 on what is ostensibly a GP frigate is pretty darn good. And given this is derived from the Long Range Discrimination Radar (emphasis on "discrimination"), I think it is safe to say that LM has employed some technology and software trickery to reduce the resolution difference between it and a dedicated X-band radar to possibly very little, if any.

On the other hand the CSC could have used CEAFAR 2 and had L, S and X band in one and not needed any other radars.
The only “trickery” then would be the modal agility of the radar.

 

[DAVID DUNLOP]

I was doing some more digging on the mostly missile defense website and found couple of other interesting articles that are related to the LRDR (now SPY-7)

Estimating the Range of LRDR
New Aegis Radar to be 100 Times More Sensitive than Current Radar

Taking these two articles together I thought it would be interesting to do a back of the envelope calc on the sensitivity of the radar proposed for the CSC. Previously we estimated the face area of the radar to be ~ 5.76 m^2 (see post 2139 on RCN thread). Using the math provided in the first article, I get an estimate of 1.23 times the range of the SPY-1 radar. However, the second article describes how the SPY-6 is actually 100x more sensitive than SPY-1, not 30 times as originally planned. It would then follow on that the radar would be 1.64 times that of the SPY-1.

On another note, the discussion of frequency had me thinking about the opacity of the earths atmosphere.

Source NASA - public domain - image from wikimedia

Further info on atmospheric attenuation

Looking at the image, the atmosphere starts becoming opaque at around 2 to 3 cm, or right at the upper edge of the X-band. This would suggest that as you go to higher frequencies, you also lose range due to atmospheric interference. At the lower end, it is near the middle of the HF-band. So useful radars for long range need to be in those bands that fall between. My understanding is that stealth technology is also less effective at lower frequencies (please correct me if I am wrong - I know it is far more complicated than just frequency).

So picking a frequency becomes a total compromise. Higher frequencies give better resolution and more accurate range since the wave length is shorter, but don't have the range due to atmosphere and are not as capable against stealth. Lower frequencies give better range but are not as capable for targeting.

I think the choice of S band is a reasonable compromise.

Hi BJS! Could not agree more. Yes, I saw both of those articles as well. Based on those facts, and compromises, I would say that Canada didn't do too badly in picking this LM AESA S Band radar for the CSC. We certainly could have done much worse (cheaper). Brings the CSC Frigate much closer to a BMD capability well. Overall, a great choice for the CSC Frigate which will be easily integrated into the CCMS 330 Combat System (CS) and weapon system by MDA as well. Don't know why Lockheed Martin didn't develop a Duel -Band ( S + X) for their SPY 7 (V) 1 LRDR. Perhaps too costly or more politics as related to the SPY 6 (V) 1 AMDR? Still doesn't bring us any closer to finding out what the square "thingies" are on the bottom of the SPY 7 (V) 1 Radar mast faces are however. Possibly an X Band terminal Fire Control Radar (FCR)? Keep smiling! Cheers!

 

[Calculus]

On the other hand the CSC could have used CEAFAR 2 and had L, S and X band in one and not needed any other radars.
The only “trickery” then would be the modal agility of the radar.

The RCN could have chosen to go with CEAFAR 2, but apparently decided that SPY-7 was the better radar.

 

[Black Jack Shellac]

The RCN could have chosen to go with CEAFAR 2, but apparently decided that SPY-7 was the better radar.

This decision may be political with LM Canada based in Canada and CEA based in Australia.

One question. Is CEAFAR a solid state radar? Never mind - it is. Certainly a version of the CEAFAR would have been suitable.

 

[John Fedup]

This decision may be political with LM Canada based in Canada and CEA based in Australia.

One question. Is CEAFAR a solid state radar? Never mind - it is. Certainly a version of the CEAFAR would have been suitable.

Agree, CEAFAR seems to have been a viable choice and I believe there was an Australian presentation to Canadian officials shortly after the T26 selection. With LM Canada having such a significant role, a CEAFAR selection was pretty unlikely.

 

[Calculus]

Agree, CEAFAR seems to have been a viable choice and I believe there was an Australian presentation to Canadian officials shortly after the T26 selection. With LM Canada having such a significant role, a CEAFAR selection was pretty unlikely.

I have to disagree. If the RCN thought it was a better system, they surely would have bought it. It was already being integrated into the Australian T26, and I'm sure there would have been no issue doing the same with the CSC. So, I have to think the RCN concluded that SPY-7 was the better system.

 

[Arclighy]

It is interesting to see that each of the Type 26 variants have gone for different radars. I'd be interested to know what the pros and cons of each radar system are? As far as l can see, and l have tried to find it, there is very little information available on Ceafar 2. It is said to be very good. I'm sure Australia has chosen it for reasons other than it's an indigenous product? Or is it a case of each nation having differing requirements and the radars chosen best meet those requirements?

 

[John Fedup]

I have to disagree. If the RCN thought it was a better system, they surely would have bought it. It was already being integrated into the Australian T26, and I'm sure there would have been no issue doing the same with the CSC. So, I have to think the RCN concluded that SPY-7 was the better system.

Your knowledge on this topic vastly exceeds mine. That being said, you are also aware of the political interference with defence acquisition. Case in point, the fighter replacement project, the RCAF knew what made sense but junior f)&jed that up. The RCN has the same issues, LM Canada has political friends that allow them to dictate things to a large extent, especially considering their CMS 330 package. I do agree the SPY7 radar integrated with CMS330 is a very capable and minimal risk solution for the CSC.

 

[Black Jack Shellac]

Your knowledge on this topic vastly exceeds mine. That being said, you are also aware of the political interference with defence acquisition. Case in point, the fighter replacement project, the RCAF knew what made sense but junior f)&jed that up. The RCN has the same issues, LM Canada has political friends that allow them to dictate things to a large extent, especially considering their CMS 330 package. I do agree the SPY7 radar integrated with CMS330 is a very capable and minimal risk solution for the CSC.

My thought on this was it being domestic, or more domestic than CEAFAR. Capability wise, I don't think there is enough information in the public domain to make an informed decision.

 

[Albedo]

I have to disagree. If the RCN thought it was a better system, they surely would have bought it. It was already being integrated into the Australian T26, and I'm sure there would have been no issue doing the same with the CSC. So, I have to think the RCN concluded that SPY-7 was the better system.

https://www.cbc.ca/news/politics/frigate-ballistic-missile-defence-canada-1.5407226

Canada's new frigates are being designed with ballistic missile defence in mind, even though successive federal governments have avoided taking part in the U.S. program.

When they slip into the water sometime in the mid- to late-2020s, the new warships probably won't have the direct capability to shoot down incoming intercontinental rockets.

But the decisions made in their design allow them to be converted to that role, should the federal government ever change course.

The warships are based upon the British Type 26 layout and are about to hit the drawing board. Their radar has been chosen and selected missile launchers have been configured to make them easy and cost-effective to upgrade.

Is CEAFAR2 BMD capable? It doesn't seem to be a current requirement for the CSC, but going with SPY-7 does allow an upgrade path to BMD capability.

 

[ngatimozart]

https://www.cbc.ca/news/politics/frigate-ballistic-missile-defence-canada-1.5407226

Is CEAFAR2 BMD capable? It doesn't seem to be a current requirement for the CSC, but going with SPY-7 does allow an upgrade path to BMD capability.

I think so, but there is not much about CEAFAR capabilities in the public domain. However, from memory, there was talk of SM3 / 6 for their Hobart DDGs at one part. Possibly one of the more knowledgeable Aussie posters might be able to shed some light on the matter.

 

[ASSAIL]

I think so, but there is not much about CEAFAR capabilities in the public domain. However, from memory, there was talk of SM3 / 6 for their Hobart DDGs at one part. Possibly one of the more knowledgeable Aussie posters might be able to shed some light on the matter.

I’m no expert on modern radars but from what I’ve read CEAFAR is capable of BMD.
This link A BIGGER SHIELD – Aegis Baseline 9 for Australia – ADBR is from 2018 so it may not be fully up to date and yes, it’s hard trying to get info on the radars. I’ve written to them to seek more details.

 

[DAVID DUNLOP]

I have to disagree. If the RCN thought it was a better system, they surely would have bought it. It was already being integrated into the Australian T26, and I'm sure there would have been no issue doing the same with the CSC. So, I have to think the RCN concluded that SPY-7 was the better system.

@DAVID DUNLOP YOUR TEXT FROM THIS POST HAS BEEN DELETED BECAUSE YOU HAVE NOT PROVIDED SOURCES TO SUPPORT YOUR ASSERTIONS. YOU HAVE BEEN SPOKEN TO ABOUT THIS BEFORE AND YOU APPEAR TO TREAT IT AS A REQUEST TO BE IGNORED RATHER THAN A REQUIREMENT.

WARNING: THEREFORE THE NEXT TIME YOU POST ON HERE AND YOU DO NOT PROVIDE SOURCES, AS YOU HAVE BEEN TOLD TO DO BY A MODERATOR, THEN YOUR FUTURE ON HERE WILL BE SUBJECT TO CONFIRMATION BY THE MODERATOR TEAM.

NGATIMOZART.

 

[Black Jack Shellac]

... It is interesting to note that LM has also been given the rights to supply this same radar to the new AB Flight 111 destroyers and not the SPY 6 (V) 1 AMDR...

Source please. Everything I see says the flight III Burkes will have SPY 6

Source 1
Source 2
Source 3
horses mouth