RWR is too accurate

[LeeyLeey]

Radar Warning Receivers and their Impact on Top tier gameplay

1. How current top tier gameplay is being affected by faulty radar modelling and RWR.
2. Why that doesn’t match up to real life.
3. How to fix the issue.

Before i even say anything I’d like to apologize for my formatting, I haven’t written a report or paper in ages and have forgotten everything about it.
Secondly I’d like to mention that this is just my opinion, no need to get personal about it.

1. Current RWR and Radar modelling

Ever since they started applying filtering to radars in war thunder, in the way of PD and MTI processing, Gaijin has gotten many things wrong. While I think they’ve improved it a little bit, it still leads to a mess that is current top tier ARB gameplay.
The biggest problem I can see is that notching is too powerful the way its portrayed in the game. Virtually every match turns into a slogfest at low altitude, because enemies constantly get filtered out during turns, which are easier to commit at low altitude. Thus it leads to similar gameplay that was present back when we first got air to air missiles almost 5 years ago. Technology since then has far surpassed the basic IR missile, yet due to how easy it is to enter the notch we still play as if it were 2019.
The radar of course is not the only problem I want to talk about. Even after adjusting the processing of pulse doppler, the RWR’s we have in game are too accurate within a degree, making notching trivially easy. RWR’s simply shouldn’t give the exact direction of the enemy. Even if it somehow were to be realistic (spoiler alert, it’s not) it doesn’t lead to good gameplay.

2. Why that isn’t realistic (not that realism matters in a game)

There is a lot of filtering that goes on in a radar, and I don’t think War Thunder makes a good effort at modelling them. To successfully enter the notch, you’d have to perfectly cancel out your radial velocity to the radar, which means flying perfectly perpendicular to the radar. Even if one were to enter the notch, modern radars have different pulse repetition frequencies to help with such cases. But disregarding PRF modes, there is something radar operators and modern radars do, which is to disable the doppler filter altogether after receiving lock. There is no reason to keep filtering the ground out after you successfully lock a target, because if it is a Single target track (which most radars use in war thunder) all the power of the radar would go into keeping that target locked.
Stepping away from radar processing, RWR’s simply are not that accurate in real life. There is a lot of mixed signals, a lot of echoes, and it simply is not realistic to rely on the RWR as a primary instrument for gaining a strategic advantage over the target.
To bring a real example to the table, the sensors for the AN/ALR-45 and ALR-67 of the F-14 move with wing surfaces, which lead to even more inaccuracies of the RWR display. One annoying “feature” Gaijin added was the fact that on some RWR’s friendly radar signals do not cause interference, which very much was a real thing. But since the community thought it was a bug they started removing that.

3. How to fix the issue.

My proposed fix is very simple. Make RWR’s less accurate, they shouldn’t be so precise to the degree where it imitates a Radar’s accuracy. With the introduction of ARH missiles in the game, the current gameplay loop will have to end, due to the fact that the missile has the ability to regain lock after the player left the notch filter. So one doesn’t have to necessarily tweak the radars of the game, the gameplay will be fixed by the players themselves in that sense.

[LeeyLeey]

I forgot to add sources to my claims, while there isn’t an exact one source, this lecture is a pretty good starting point.
https://www.ll.mit.edu/sites/default/files/outreach/doc/2018-07/lecture%208.pdf

[GeneralArmchair]

@LeeyLeey

Virtually every match turns into a slogfest at low altitude, because enemies constantly get filtered out during turns, which are easier to commit at low altitude.

People aren’t going low to better notch missiles. I might get my terms slightly wrong because I’m not an expert on the topic, but the reason everyone stays low is because multipath causes radar missile tracking to become useless against low flying targets.

Anecdotally I don’t feel like the majority of players at top tier even know about notching. They just know that they’re safe against radar missiles if they stay low.

[LeeyLeey]

Sure, you’re safe against radar missiles if you fly treetop level so proximity fuzes stop working, but your own missiles will have no energy to work with against higher targets. But due to the way these mechanics all fold onto eachother, that is a moot point, since radar isn’t what it should be.

[Miraz05]

Nerfing RWR wont fix anything. It would just make the situation even worse for some jets.

[LeeyLeey]

In this post I’m more referring to the more “modern” end of war thunder, the top tier. I am not talking about nerfing RWR’s that already are limited in their accuracy, such as the ones you can find on the mirage f1.

[Flame2512]

@LeeyLeey

To successfully enter the notch, you’d have to perfectly cancel out your radial velocity to the radar, which means flying perfectly perpendicular to the radar

That’s not the case. For example the notch filter on the AN/AGP-59 filtered out everything within 110 knots either side of Main Beam Clutter. That’s a pretty wide window for you to get yourself into.

[LeeyLeey]

The APG-59 is not a modern radar though. It has limited LDSD capability. And in the era where such radars can be seen, 10.7-11.3 i’d wager notching should be a valid gameplay mechanic, because the missiles aren’t reliable themselves.

[TheArcticFoxxo]

@LeeyLeey

The APG-59 is not a modern radar though.

It was deployed in the early 70s, I’d call that modern for the standards we are talking on.

@LeeyLeey

It has limited LDSD capability.

It’s a pulse doppler radar. It has HMP, MMP, and LMP modes, as well as a wide range of usability and a high knowledge ceiling for use.
It’s entirely digitized on the F-4S with the AWG-10B suite, too. You don’t even need to interpret it on multiple levels.

@LeeyLeey

And in the era where such radars can be seen, 10.7-11.3 i’d wager notching should be a valid gameplay mechanic, because the missiles aren’t reliable themselves.

In that same era, radars such as the AN/APG-66 existed. That has a gate width of 55kn.
The AN/APG-63 is upwards of 100kn, with HPRF lowering it down to 60kn.

Notching absolutely is a valid mechanic. No matter how “modern” a radar is, the velocity gates are quite expansive, and PRF modes do little to combat it.

[TheArcticFoxxo]

1

@LeeyLeey

The biggest problem I can see is that notching is too powerful the way its portrayed in the game. Virtually every match turns into a slogfest at low altitude, because enemies constantly get filtered out during turns, which are easier to commit at low altitude.

There is no issue in this. Ranges that aircraft can be detected at are decreased by means of 20-40% when presented with a backdrop, and on some radars it may even halve the effectiveness entirely. Primarily some models of PESA.

@LeeyLeey

The radar of course is not the only problem I want to talk about. Even after adjusting the processing of pulse doppler, the RWR’s we have in game are too accurate within a degree, making notching trivially easy. RWR’s simply shouldn’t give the exact direction of the enemy. Even if it somehow were to be realistic (spoiler alert, it’s not) it doesn’t lead to good gameplay.

Accuracy of RWRs such as the ALR-56M come down to fractions of a degree against E-J band radars. K/L band radars present an inaccuracy of upwards of 3-5dg, and C/D bands are inaccurate to the degree of 15dg.
Simply saying that it feels “too accurate” does not mean that it is not that accurate realistically. Especially when it comes to STT locks, which is one of the most common things to encounter in an ARB match.
It absolutely is realistic. Some DL and SAD systems can compute the signal strength and direction and give an approximate location to enemies, as well.

2

@LeeyLeey

There is a lot of filtering that goes on in a radar, and I don’t think War Thunder makes a good effort at modelling them. To successfully enter the notch, you’d have to perfectly cancel out your radial velocity to the radar, which means flying perfectly perpendicular to the radar.

You don’t at all. As somebody else already mentioned, the leniency in the velocity gate of most PD radars is large, and it favors cold contacts with a ~30% bias.

@LeeyLeey

Even if one were to enter the notch, modern radars have different pulse repetition frequencies to help with such cases.

As I’ve said in a previous comment, these PRF modes do little to combat notching, and in turn may decrease the accuracy of the lock.

@LeeyLeey

But disregarding PRF modes, there is something radar operators and modern radars do, which is to disable the doppler filter altogether after receiving lock. There is no reason to keep filtering the ground out after you successfully lock a target, because if it is a Single target track (which most radars use in war thunder) all the power of the radar would go into keeping that target locked.

Radars, no matter how modern, do not take into account of backdrop during a lock as it actively filters it out. To disable a PD filter would mean to take a gamble of losing a lock the second it is acquired, and there is no sense to your system freely changing to a lesser mode that will almost 100% result in immense clutter.
Even then, the false alarm rate of switching from a doppler mode to a basic pulse mode ranges from 70-90%. Just as I said in the previous paragraph, no radar will drop its doppler filter during lock, as it will almost always result in lost acquisition.

@LeeyLeey

Stepping away from radar processing, RWR’s simply are not that accurate in real life. There is a lot of mixed signals, a lot of echoes, and it simply is not realistic to rely on the RWR as a primary instrument for gaining a strategic advantage over the target.

That’s exactly what adaptive filters are for. It will only acknowledge signals that it knows to be from common radars, and will identify target types based off of stored information. That’s exactly what SAS systems for EW platforms combat, as well as some modern radars such as the AN/APG-81 and APG-83, as well as the N036. They change pulse repetition frequencies, as well as its output frequency, for the purposes of enemy detection and masking the source of the emissions.
The RWR is one of the VERY few systems you use in BVR engagements. When you aren’t using your radar, you’re using your RWR. Sometimes your RWR can be tied to a DL display or TSD, other times you have no mapping or datalink system to rely on.

@LeeyLeey

To bring a real example to the table, the sensors for the AN/ALR-45 and ALR-67 of the F-14 move with wing surfaces, which lead to even more inaccuracies of the RWR display.

Much like the RWR hardpoints on the stabilators, this makes no difference in the detection of enemy radars. The PRF and dBM characteristics of the radar wave are computed, with RWRs such as the aforementioned ALR-56M being capable of calculating directional waves of -60 → -15dBM with an accuracy of <5dg. Most American RWRs don’t base the direction of the signal based off of the placement of the RWR node, but the signal itself after applying signal/noise filters.

@LeeyLeey

One annoying “feature” Gaijin added was the fact that on some RWR’s friendly radar signals do not cause interference, which very much was a real thing. But since the community thought it was a bug they started removing that.

What interference would they cause? The only interference that could be caused by friendly radars is that of traditional interference, and even then a friendly and an enemy radar operating on the exact same frequency must be illuminating you from the same direction.

3

@LeeyLeey

My proposed fix is very simple. Make RWR’s less accurate, they shouldn’t be so precise to the degree where it imitates a Radar’s accuracy.

I mean… That’s its exact purpose. To be able to accurately detect radar signals and relay the exact direction. In the case of ALR-45/67, the F-14 has 4 antennae for its RWR suite. 4. If it couldn’t accurately compile signals and compute the exact direction that the signal had come from, it would act exactly as the SPO-10 does, as the SPO-10 does not compute each specific waves direction.

@LeeyLeey

With the introduction of ARH missiles in the game, the current gameplay loop will have to end, due to the fact that the missile has the ability to regain lock after the player left the notch filter. So one doesn’t have to necessarily tweak the radars of the game, the gameplay will be fixed by the players themselves in that sense.

With the introduction of ARH missiles, BVR engagements will be incentivized.
BVR does not occur at low altitude, as missile range at low altitude is extremely short.
Players at low altitude can still easily notch and skew, so… I’m not really sure how this will change anything but missile capabilities.

[LeeyLeey]

Even if what you said were to be true, how do you think the current implementation is better gameplay wise?

What will end up happening is this game turning into another DCS, where PVP combat is very linear.
Players are incentivized to simply put the missile on their 3/9 line and notch the missile in a few seconds, and then reengage, pushing the fight into a furball. You just want this game to continue being horrible like it is.

We are not constrained by restrictive ROE and half working IFF. We are not constrained by missiles which do not work. We should perfectly be able to utilize multiship tactics, yet because of the implementation of radar mechanics, all the enemy has to do is get into the notch filter for a second. Leaving you no choice but to enter WVR.

You really think pilots in real life, anywhere, are gonna utilize notching missiles? No, because it is not a real way to defeat missiles. They either don’t get within the WEZ of the enemy or they defeat missiles kinematically.

It is stupid both gameplay wise, and real life wise. Many of your replies have holes in them, like the RWR on the f-14, which has plenty of problems with false contacts and accuracy.

[TheArcticFoxxo]

@LeeyLeey

Even if what you said were to be true, how do you think the current implementation is better gameplay wise?

It allows for the most basic of air-air engagements? How do you think it’s bad?

@LeeyLeey

What will end up happening is this game turning into another DCS, where PVP combat is very linear.
Players are incentivized to simply put the missile on their 3/9 line and notch the missile in a few seconds, and then reengage, pushing the fight into a furball. You just want this game to continue being horrible like it is.

That’s… The entire point of air to air combat, and is arguably better than the state of the game right now. You joust and maneuver through BVR fights, and if you survive, it eventually divulges into an actual dogfight or simply a closer range kill.
Compare this to current top tier.
You climb, you joust with SARH missiles, and once you dodge those, you get into an actual dogfight or simply a close range kill.

What difference do you see?

@LeeyLeey

We are not constrained by restrictive ROE and half working IFF. We are not constrained by missiles which do not work. We should perfectly be able to utilize multiship tactics, yet because of the implementation of radar mechanics, all the enemy has to do is get into the notch filter for a second. Leaving you no choice but to enter WVR.

That’s quite literally how modern aerial engagements work IRL, though. That’s the entire reason why terminology like “notch” and “skew” exist. It’s exactly how IRL engagements can be avoided and defended upon.
We are dealing with late 1960s tech in modernized forms. AIM-7Ms and R-27ERs are nothing but 1960s-1970s missiles with better propulsion and characteristics. They’re still nothing but a SARH missile. They are extremely easy to dodge, and unlike ARH missiles, always force the attacker to stay engaged.

@LeeyLeey

You really think pilots in real life, anywhere, are gonna utilize notching missiles? No, because it is not a real way to defeat missiles. They either don’t get within the WEZ of the enemy or they defeat missiles kinematically.

11FX here, they’re trained meticulously on it. It absolutely is a real way to defeat missiles, though it is not the be-all-end-all of ARH engagements. It is, however, for non-DL capable SARH missiles.
What WEZ of the enemy? If you’re being fired on, you’re already within the WEZ.
As for kinematic missile defeats, the only purpose of this is against ARH missiles, which there is only 1 of in-game… And believe it or not, you have to defeat it kinematically! You either turn cold until its range depletes and it cannot turn (the AIM-54C can’t turn to begin with, so…), or you skew it.

@LeeyLeey

It is stupid both gameplay wise, and real life wise. Many of your replies have holes in them, like the RWR on the f-14, which has plenty of problems with false contacts and accuracy.

I’m sorry you feel that way, but that doesn’t reflect on reality or in-game.

Many of my replies have holes in them? You displayed a blatant lack of understanding of RWR to begin with. You believed the wing sweep of the F-14 has anything to do with the accuracy of its RWR… It doesn’t.

[LeeyLeey]

For being a vet you sure get a lot of things wrong. And yes it absolutely does
https://www.youtube.com/watch?v=c65oeNWEbug

11FX Is for air force aircraft last i checked, which doesn’t include the f14a early, f14a, f14b, the f14bu, or the f14d.

[LeeyLeey]

@TheArcticFoxxo

That’s… The entire point of air to air combat, and is arguably better than the state of the game right now. You joust and maneuver through BVR fights, and if you survive, it eventually divulges into an actual dogfight or simply a closer range kill.
Compare this to current top tier.
You climb, you joust with SARH missiles, and once you dodge those, you get into an actual dogfight or simply a close range kill.

One system promotes skilled gameplay, the other promotes dumb easy mechanics like getting into the notch filter. People would actually have an incentive to use altitude to their advantage for longer range missile shots.

[TheArcticFoxxo]

@LeeyLeey

And yes it absolutely does
https://youtu.be/c65oeNWEbug

This video was made almost a full year before the release of the F-14B, and before the full-fidelity RWR implementation done this past summer.
DCS is notorious for botching radar and RWR, even lacking an IFF implementation as a whole. Hell, they even made a detailed changelog for the F-14A, F-14B, and the upcoming ALR-46 for the Phantoms.
This included

Info on exact beam parameters, as well as gain / speed, as well as simulated sound for the specific signals received.

You’re working on outdated footage, and basing an entire addressed claim on it. It’s been announced that they would change it, it’s been fixed, and it now works as it normally would.

The only thing fucking it up is Eagle Dynamic’s horrible multiplayer hosting…

@LeeyLeey

11FX Is for air force aircraft last i checked, which doesn’t include the f14a early, f14a, f14b, the f14bu, or the f14d.

The Tomcat had nothing to do with this.

[TheArcticFoxxo]

@LeeyLeey

One system promotes skilled gameplay

Skilled gameplay is notching and skewing. Without it, it would simply be a race to get as far as possible and spam as many unavoidable missiles as possible.

@LeeyLeey

the other promotes dumb easy mechanics like getting into the notch filter.

If you find them easy on each and every aircraft, then by all means you have grounds to argue on.
Just come back to me when you’ve flown enough with SPO-2/10/15, and so on. Getting within +/- 3dg of a direction to notch an enemy is much harder when your RWR has 40 degrees of deadspace.

@LeeyLeey

People would actually have an incentive to use altitude to their advantage for longer range missile shots.

That’s exactly what these defensive maneuvers incentivize? Without notching, it’s either push up and die or run away and let them chase you for half an hour. Without notching, missiles like the R-27ER that go almost 20% faster than its alternatives would be inescapable.

[_ShadowFang]

I wouldn’t argue too much with an 11FX, especially since they are going to be trained to use those exact systems. And take it from a 2A9X4 who tests and fixes them, you dont really understand enough about these systems.

The system in game is fairly accurate to real life yet simplified (in terms of threat signals) to be effectively used in normal matches.

[LeeyLeey]

Bringing the missile down to thicker air? Beaming?

[TheArcticFoxxo]

@_ShadowFang

I wouldn’t argue too much with an 11FX, especially since they are going to be trained to use those exact systems. And take it from a 2A9X4 who tests and fixes them, you dont really understand enough about these systems.

I started out as a 2A3X1 backshop, if I had started out flying, I think I’d be a much happier person overall.

@_ShadowFang

2A9X4

Look at you and your big boy stuff! Big ole… Fat stuff. Big ole ugly stuff.
Were/are you active?

[TheArcticFoxxo]

@LeeyLeey

Bringing the missile down to thicker air? Beaming?

I believe I’ve mentioned that in an earlier comment, we’ve taken this to DMs to discuss it already.