Radar/Sensors Discussion

[Czechnology]

Read the title. I know we're getting the AN APQ-120, what do we know about the radar system? I've not found much good documentation on it. Any good range figures? Was it as terrible about ground clutter as I keep hearing? We have any good radars in DCS that can be used as a vague simulacra?

TISEO, are we getting that? Just one or both of the Phantoms we're getting, if we're getting it at all?

 

[LanceCriminal86]

7 hours ago, Czechnology said:

Read the title. I know we're getting the AN APQ-120, what do we know about the radar system? I've not found much good documentation on it. Any good range figures? Was it as terrible about ground clutter as I keep hearing? We have any good radars in DCS that can be used as a vague simulacra?

TISEO, are we getting that? Just one or both of the Phantoms we're getting, if we're getting it at all?

 

TISEO will the be the second E that comes with DMAS and factory slats etc. TISEO was on the '71+ serial jets. First released jet will be the older 66-69 serials with retrofitted slats.

[JNelson]

7 hours ago, Czechnology said:

Read the title. I know we're getting the AN APQ-120, what do we know about the radar system? I've not found much good documentation on it. Any good range figures? Was it as terrible about ground clutter as I keep hearing? We have any good radars in DCS that can be used as a vague simulacra?

TISEO, are we getting that? Just one or both of the Phantoms we're getting, if we're getting it at all?

 

The AN/APQ-120 is a pulse radar and it displays the raw returns (with little filtering). You will need to distinguish between ground clutter and actual targets. The AI (range setting) goes up to 50 nmi, inside AI range you can make an STT lock provided the return is large enough. The manual even reports the ability to spotlight (manually guide the antenna) targets even further, the range scale goes all the way up to 200 nmi.

[Czechnology]

17 hours ago, JNelson said:

The AN/APQ-120 is a pulse radar and it displays the raw returns (with little filtering). You will need to distinguish between ground clutter and actual targets. The AI (range setting) goes up to 50 nmi, inside AI range you can make an STT lock provided the return is large enough. The manual even reports the ability to spotlight (manually guide the antenna) targets even further, the range scale goes all the way up to 200 nmi.

Have any resources to read on this info? Interested in the "spotlight" thing especially.

[DSplayer]

1 hour ago, Czechnology said:

Have any resources to read on this info? Interested in the "spotlight" thing especially.

I’d assume the spotlight feature is similar to what modern jets like the F-18 and F-16 have. It’s basically a super narrow search pattern so you can try to get a track on something. When compared to the Tomcat, I think it’s similar to the super search function that we have already. All of this could be wrong however since I’m not too knowledgeable on the Phantom’s systems.

[Czechnology]

Might be what he's talking about, but they made a clarification between manually guiding/spotlighting the radar and STT. I've done a good bit of reading on the F-4 but haven't seen any good details on the radar other than the cliff notes, pulse radar with poor low alt performance, 30-40 miles reliable range.

5 minutes ago, DSplayer said:

I’d assume the spotlight feature is similar to what modern jets like the F-18 and F-16 have. It’s basically a super narrow search pattern so you can try to get a track on something. When compared to the Tomcat, I think it’s similar to the super search function that we have already. All of this could be wrong however since I’m not too knowledgeable on the Phantom’s systems.

 

Also, to open a second line of discussion, the RWR. What info do we have on the RWR we'll be getting for the different versions?

[LanceCriminal86]

Whatever you can find, it's the APR-36/37. When built most Es after the first batch through mid '68 had the APS-107, but the performance was considered to be terrible, and after VN jets were upgraded with APR-36/37.

 

It looks like the older Phantoms had the 25/26, and really late ones had ALR-46 but I believe the APR-36/37 are currently what's planned from the release posts.

Edited November 9, 2022 by LanceCriminal86

[SgtPappy]

2 hours ago, LanceCriminal86 said:

Whatever you can find, it's the APR-36/37. When built most Es after the first batch through mid '68 had the APS-107, but the performance was considered to be terrible, and after VN jets were upgraded with APR-36/37.

 

It looks like the older Phantoms had the 25/26, and really late ones had ALR-46 but I believe the APR-36/37 are currently what's planned from the release posts.

 

I'm quite excited to see what is in store with the APR-36/37 and its limitations.

The Israelis were apparently unable to detect CW launch signals from the SARH SA-6, which is odd since I thought that X-band signal was right in the range of the stock APR-36/37. So I wonder if we'll have similar problems with the SA-6 and more modern systems in the game.

Of course I might also be missing something or taking that historical tid bit out of context... not much info on what they did to solve the issue within the two days of the start of the Yom Kippur war.

Edited November 9, 2022 by SgtPappy

[Harlikwin]

8 hours ago, Czechnology said:

Might be what he's talking about, but they made a clarification between manually guiding/spotlighting the radar and STT. I've done a good bit of reading on the F-4 but haven't seen any good details on the radar other than the cliff notes, pulse radar with poor low alt performance, 30-40 miles reliable range.

 

 

I mean it is a pulse radar with little filtering, so low alt performance should be terrible due to sidelobe and clutter issues. Look down should in general be bad, but its going to be better at higher altitudes and lower grazing angles. Its also gonna depend alot on the target/aspect/strength of return. Best case its gonna be fine at med/high alt in lookup/co-alt situations. 

2 hours ago, SgtPappy said:

I'm quite excited to see what is in store with the APR-36/37 and its limitations.

The Israelis were apparently unable to detect CW launch signals from the SARH SA-6, which is odd since I thought that X-band signal was right in the range of the stock APR-36/37. So I wonder if we'll have similar problems with the SA-6 and more modern systems in the game.

Of course I might also be missing something or taking that historical tid bit out of context... not much info on what they did to solve the issue within the two days of the start of the Yom Kippur war.

 

More modern systems for sure. But who knows if it will be modeled. Stuff like 70's era SA-10 were using basic LPI/LPD techniques even back then. But ED's modeling of SAM radars and actual SAM guidance techniques for even stuff like the single digit sams is not good, esp the SA-2 and the SA8, i.e. in terms of not modeling actual guidance modes or the optical trackers correctly. And honestly I do not think it is a priority for them to fix it. 

 

Edited November 9, 2022 by Harlikwin

[Quid]

HAVE DOUGHNUT-Tactical (Vol II) (published 1 August 1969, declassified 23 Mar 2000, and released publicly 29 October 2013 through the George Washington University's National Security Archive) discusses the APQ-72 (F-4B), APQ-109 (F-4D), APQ-120 (F-4E) and AWG-10/APG-59 (F-4J) performance vs. the MiG-21.  Some summations:

The APQ-109 acquired the MiG-21 on average 5-10% further away possibly due to the difference in beam width and redesigned radar reflector.

Head-on co-altitude, average detection was 20NM with an average lock-on achieved at 15NM. [1]

Tail aspect detected at 25NM and tracked at 17NM on average. [1]

Abeam, detection averaged 35NM and tracked at 28NM. [1]

Ground clutter at lower altitudes complicated the radar tracking problem.  Both the APQ-109 and APQ-120 were practically blind looking down, and using the auto-acquisition mode in a look-down scenario is also not useful as it only sweeps 12,500 feet, leaving no-time for a forward quarter shot. [2]

The F-4B's APQ-72 performed comparably, but aspect was not provided:

5-15K Feet saw a max detection of 32NM, and an average 20-25NM.  Track range maximum was 18NM and average 15NM.  [3]

15-30K Feet saw a maximum detection of 40NM, average of 30-35NM.  Track range was 27NM max and 25NM average.  [3]

The F-4J's APG-59 fared far better in Pulse Doppler modes; apparently the pulse mode was worse at high altitudes.

The APG-59 averaged 45NM forward-quarter detection with a maximum range of 62NM, and on two occasions, the F-4J spotted the MiG-21 immediately upon takeoff from 15K feet (look-down), detecting, acquiring, and tracking by 50NM. [4]

There's some things to keep in mind, of course; I have no idea how they tweaked the APQ-120 (if at all) from 1969 to the mid-1970s (roughly the period the first F-4 Headblur releases is supposed to be representing); the document mentions an expanded auto-acquisition mode to 30,000 feet would be desirable, but this still doesn't change the limitations of a pulse radar looking down, and I don't know if "desirable" became a requirement and actually happened..  Also, if the F-4E is coming with AIM-7Es, it's good to have SA earlier on, but your engagement range is still less than the average head-on tracking range of the APQ-120.  Also, although this shouldn't need to be stated, a large fighter or a bomber would be seen further away.

Suffice to say, I don't plan on being able to see a MiG-21 rooting around in the dirt from long ranges, at least until a model with a PD radar is released.

Sources:

1. Defense Intelligence Agency, HAVE DOUGHNUT-Tactical (Vol II), 1 August 1969 (Declassified 23 Mar 2000), 1-33.

2. DIA, HAVE DOUGHNUT, 1-34.

3. DIA, HAVE DOUGHNUT, 2-36.

4. DIA, HAVE DOUGHNUT, 2-37.

Edited November 10, 2022 by Quid

[Exorcet]

It's interesting that according to this video the F-4 has better radar lookdown performance than the DCS F-16 or F-18.

[303_Kermit]

On 11/9/2022 at 4:42 PM, SgtPappy said:

I'm quite excited to see what is in store with the APR-36/37 and its limitations.

The Israelis were apparently unable to detect CW launch signals from the SARH SA-6, which is odd since I thought that X-band signal was right in the range of the stock APR-36/37. So I wonder if we'll have similar problems with the SA-6 and more modern systems in the game.

Of course I might also be missing something or taking that historical tid bit out of context... not much info on what they did to solve the issue within the two days of the start of the Yom Kippur war.

 

I would be very cautious with Israeli combat reports. They're seriously confusing. I do believe it's on purpose. Nothing strange about it to be honest. There are full of stories, when you never know what plane pilot flew. You may only assume or suppose, that it's Phantom, because pilot once says "we" and on the other time during the same story says "me".

Glory to the Kheil HaAvir, but they're not quite... Most reliable source of information. They're rather a source of various MiG-parts.

On 11/10/2022 at 2:07 AM, Exorcet said:

It's interesting that according to this video the F-4 has better radar lookdown performance than the DCS F-16 or F-18.

F-4J has Pulse doppler radar. Navy had much better device since they resigned from M-61A1 Vulcan in the nose. That's why, without gun in the nose their radar has bigger antenna and it's a quite different device, than USAF F-4E Pulse radar. F4E posese a ground clutter filter. It helps detecting airborne tgts if they fly lower, but not close to the ground, by limitting and separating signals that comes back from the same direction, but after different time period. So If AGL is big enough you may detect someone who flies lower. Most cases however MK 1 Eyeball will be more effective considering detection range of APQ-120

I'm amazed by something another. 9:57 "There was a water in Datalink compartment". F-4J had datalink on board?

My best regards
Kermit

Edited November 15, 2022 by 303_Kermit

[Dragon1-1]

Possibly a Link 4 for carrier landings.

[Hobel]

I wonder what the firing of the Fox1 will look like in the F4, does the target get a warning immediately after the Fox1 is launched?

In DCS it is the case that every launch of a Fox1 triggers an RWR missile warning.

Does the Aim7 see the back radiation from the target on 20-30nm?
or is it first guided into the vicinity with data link/radio signals?

[SgtPappy]

7 hours ago, 303_Kermit said:

I would be very cautious with Israeli combat reports. They're seriously confusing. I do believe it's on purpose. Nothing strange about it to be honest. There are full of stories, when you never know what plane pilot flew. You may only assume or suppose, that it's Phantom, because pilot once says "we" and on the other time during the same story says "me".

Glory to the Kheil HaAvir, but they're not quite... Most reliable source of information. They're rather a source of various MiG-parts.

Agreed but it's such a mystery, I cant help but to wonder what's true! At least from a RWR perspective.

Edited November 11, 2022 by SgtPappy

[Bremspropeller]

8 hours ago, 303_Kermit said:

I'm amazed by something another 9:57 "There was a water in Datalink compartment". F-4J had datalink on board?

"Gray Ghosts" pg 121:

Quote

"A carry-over from the limited F-4G experiment was the AN/ASW-25 data-link, though the Fleet was still not ready to utilize this gear when the aircraft entered service in 1967. William D. Knutson, CO of VF-33 pointed out that "neither the E-2A Hawkeye nor the carrier was really up to speed on using it for control. It was not used in combat."

It's not just for automated carrier-landings, but also for giving steering-cues or -commands for such equipped aircraft. Seems like the trouble wasn't on the F-4J's end, though.

 

[Harlikwin]

6 hours ago, Hobel said:

I wonder what the firing of the Fox1 will look like in the F4, does the target get a warning immediately after the Fox1 is launched?

In DCS it is the case that every launch of a Fox1 triggers an RWR missile warning.

Does the Aim7 see the back radiation from the target on 20-30nm?
or is it first guided into the vicinity with data link/radio signals?

Aim-7 doesn't have a DL (at least the early ones, IDK about the last ones like the P). The earlier ones in fact were limited by radar TX power rather then their max aero ranges. 

 

[r4y30n]

Does anyone know the relationship between the AWG-9 in the F-14 and the AWG-10 in the F-4J? Surely the Phantom unit came first… But then why are they not chronologically numbered?

[Quid]

6 hours ago, r4y30n said:

Does anyone know the relationship between the AWG-9 in the F-14 and the AWG-10 in the F-4J? Surely the Phantom unit came first… But then why are they not chronologically numbered?

For the numbering, I'm guessing because the AWG-9 entered development before the AWG-10; the AWG-9 conceptually started with the F6D Missileer program and actually began development for the F-111B.  Something else, the AN/AWG-9 designator applies to the F-14A/B's radar while the AN/AWG-10 designator is the F-4J's fire control (or missile control) system working with its AN/APG-59 pulse doppler radar (the F-14's fire control system is the AN/AWG-15).  I'm not nearly as well read on the F-4 as I am the F-14, but even the HAVE DOUGHNUT Tactical manual separates AWG-10 performance from APG-59 performance specifically WRT fire control (e.g., "The capability of the AWG-10 missile control system was partially degraded by the inherent weakness associated with the tactical employment of the pulse doppler mode of the APG-59 radar" [1]).

I'm aware that some folks use the AWG-10 designator to refer to the F-4J's radar, but that doesn't seem correct - rather the AWG-10 is the fire control system used in conjunction with the APG-59 radar.  Either way, I'll let a Phantom Phanatic explain because they could do a lot better than me.

Sources:

1. Defense Intelligence Agency, HAVE DOUGHNUT-Tactical (Vol II), 1 August 1969 (Declassified 23 Mar 2000), 2-37.

Edited November 12, 2022 by Quid
Grammar

[JNelson]

On 11/9/2022 at 7:57 AM, Czechnology said:

Have any resources to read on this info? Interested in the "spotlight" thing especially.

 

On 11/9/2022 at 9:18 AM, DSplayer said:

I’d assume the spotlight feature is similar to what modern jets like the F-18 and F-16 have. It’s basically a super narrow search pattern so you can try to get a track on something. When compared to the Tomcat, I think it’s similar to the super search function that we have already. All of this could be wrong however since I’m not too knowledgeable on the Phantom’s systems.

There is no pattern when you spotlight, the antenna will simply point where you put the antenna hand control azimuth and elevation. There are two modes for the spotlight which first requires a little explanation.

For angle tracking the beam must be conically scanned (beam goes in a circular path around the antenna axis). This is achieved by nutating the antenna feedhorn at around 60 Hz. This is necessary for these old radars which use conical scanning as apposed to monopulse for steering their antenna when tracking a target. This effectively widens the beam on average to around 6.7 degrees compared to 3.7 degrees. Most of the modes have the radar nutating by default as this generally gives a wider search area at the cost of a lower average power per unit solid angle.

The two spotlight modes are engaged with the action switch above AI ranges (100 nmi, 200 nmi):

• Half action - spotlight mode with nutation (6.7 degrees)
• Full action - spotlight mode without nutation (3.7 degrees)

Technically you can use spotlight at AI ranges and below but this is just called acquisition and a full action will command an automatic track.

Edited November 12, 2022 by JNelson

[Aussie_Mantis]

On 11/8/2022 at 5:28 PM, Czechnology said:

Read the title. I know we're getting the AN APQ-120, what do we know about the radar system? I've not found much good documentation on it. Any good range figures? Was it as terrible about ground clutter as I keep hearing? We have any good radars in DCS that can be used as a vague simulacra?

TISEO, are we getting that? Just one or both of the Phantoms we're getting, if we're getting it at all?

 

Trawling through this, nobody's mentioned CAA.

Phantoms with AN/APG-120(V)10 or above radars will have CAA, which helps with boresight acquisitions while trying to counter ground clutter, most effective when looking down at about 10 degrees.

 

From what I know and have tried of the F-4E in other sims, your missiles have an effective range of maybe 10 nautical miles in a headon. Maybe less, dependent on altitude. Do not rely on the radar's ability to look down, it's terrible at best and sub-par at worst, but of course, it helps if the target you're scanning for is massive or heading towards you at high closure.

Sparrows should work best at decently high closure rates of ~1300-1400 feet per second, fired at ~7.5nm-10nm if it's the E variant, 10nm-17nm if the F variant. Reliability is meh. The radar's honestly going to be the bigger problem- trying to look or lock down low or while low (below ~10000 feet) is going to be tantamount to suicide..

Edited December 19, 2022 by Aussie_Mantis

[JNelson]

On 12/19/2022 at 12:50 PM, Aussie_Mantis said:

Trawling through this, nobody's mentioned CAA.

Phantoms with AN/APG-120(V)10 or above radars will have CAA, which helps with boresight acquisitions while trying to counter ground clutter, most effective when looking down at about 10 degrees.

 

From what I know and have tried of the F-4E in other sims, your missiles have an effective range of maybe 10 nautical miles in a headon. Maybe less, dependent on altitude. Do not rely on the radar's ability to look down, it's terrible at best and sub-par at worst, but of course, it helps if the target you're scanning for is massive or heading towards you at high closure.

Sparrows should work best at decently high closure rates of ~1300-1400 feet per second, fired at ~7.5nm-10nm if it's the E variant, 10nm-17nm if the F variant. Reliability is meh. The radar's honestly going to be the bigger problem- trying to look or lock down low or while low (below ~10000 feet) is going to be tantamount to suicide..

 

There is a post about the CAA here: 

 

[Peter5on]

As we know rwr sounds are going to be made by Heatblur for F-4 and F-16 Handoff mode so this video might get helpful.

in this video you can hear all kinds of sounds and on 12:40 they even simulate sa-3 sound for rwr cos they have this radar simulator (use headphones)

 

 

[Kalasnkova74]

On 11/9/2022 at 9:42 AM, SgtPappy said:

I'm quite excited to see what is in store with the APR-36/37 and its limitations. 

The Israelis were apparently unable to detect CW launch signals from the SARH SA-6, which is odd since I thought that X-band signal was right in the range of the stock APR-36/37. So I wonder if we'll have similar problems with the SA-6 and more modern systems in the game.

Of course I might also be missing something or taking that historical tid bit out of context... not much info on what they did to solve the issue within the two days of the start of the Yom Kippur war.

 

In summary, this was because the brand new SA-6 was not detectable by Western defensive avionics engineered for earlier systems. As such , I’d expect the F-4E’s module’s RWR to detect the Gainful’s guidance system. Page 48 of a USAF paper submitted on the October 1973 conflict outlines this further : 

“On 6 October 1973, the S.A-6 was being employed for
the first time anywhere in the world, and it was not affected by the ECM, chaff, or flares then employed by the IAF'.

The Israeli ECM equipment was designed for the S.A-2 and S.A-3 and not for the wider frequency band over which the SA-6 radar operated. Even if the ECM were effective, the SA - 6 could have been launched under optical control.

Chaff, which
the IAF used extensively, also had to be tuned to the proper frequencies,IOW . cut to the proper lengths.The Israeli
flares were intended to divert the SA-7; they could not
affect the command plus semi-active radar homing guidance of the SA-6.”

Full document: 

Edited February 20, 2023 by Kalasnkova74

[Mobius_11804]

Hi there, since there were so many grey-nosed german F-4's in the trailers, i've got a litte curious.

The grey nose indicated the ICE Upgrad to the F-4F with the Huges APG-65 RADAR and henceforth AMRAAM capability.

Are we going to get that as well???