Modern ARH SAM Guidance: Multipath Rejection and Low-Altitude Tracking

Welcome to my second suggestion ! This one is about multipathing in a modern era backround; suggesting a rework of the comportment of ground-to-air ARH (actve radar homing) missiles against low-flying targets. Prepare a good couch, cup of coffee and maybe Aspirin for later !
Your opinion is welcome, poll is at the end

Close Air Support (CAS) plays a major role in modern conflics; and so are weapons designed to avoid enemy aerial forces. They have evolved drastically trough the ages; started with a quadruple trench-war machine gun mounted on a truck to missiles creating dead-zones with radius up to 100km, and weights more than 500kg. But avoiding those missiles have never been easy; with each generation cames weaknesses.

Quick call-back : origins of multipathing

One of the oldest tricks in the book is multipath: when a radar signal bounces off the sea, the ground, or any nearby surface on its way to and from a target, the receiver picks up two overlapping copies of the same return (one direct, and a reflect on the ground) arriving from slightly different angles at nearly the same time.

The radar can struggle to tell them apart, and the reflected copy can drag its tracking solution toward a “phantom” position, sometimes right down toward the surface itself. For decades, this was a genuine exploitable weakness — the reason sea-skimming anti-ship missiles fly at wave-top height, and why a low-flying aircraft could sometimes vanish into ground clutter. This post looks at how that weakness works, how much modern radar processing has closed it, and where the physics still leaves a real tinnier gap.

image

Exemple of ground clutter.

Multitude of software and hardware updates have been made trough the 2000’s all the way to today in the objective of fighting against those clutter.

In-game, games at upper BR’s are ruled by air domination. Sadly most anti-air at toptier are quickly abused by multipathing targets and pop-up attacks or low-flying/hovering attackers (helicopters). Any target flying low (currently ± 30m) can escape any incoming ARH missiles, representing 13 out of 24 12.+ total missiles (>50%).

IRL comparaison.

‘Magnum!’ Flying A Wild Weasel Mission With The Tornado ECR And The F-35 - The Aviationist

In practice, multipath is no longer a reliable evasion method against modern air defenses. Today’s radars counter it directly through fine angular resolution, adaptive sidelobe cancellation, frequency agility, and other complex methods (that are quickly explained further). As a result, real-world evasion today relies on active, trainable tactics (by example : notching, terrain masking, chaff/jamming, going cold) while multipath survives mainly as a residual, partial effect against older or lower-tier systems rather than a real tactic against modern ones.

Example of an imaginary modern SEAD mission of the Luftwaffe against Buk anti-air

1. Intelligence and mission planning

Before any aircraft launches, planners build an Electronic Order of Battle from prior SIGINT/ELINT collection — known or suspected SAM sites, likely engagement ranges, and radar activity patterns. Without a dedicated EW platform doing real-time jamming/geolocation, this pre-mission picture matters even more, because the strike aircraft won’t have a Growler-type asset actively mapping and suppressing emitters as it goes.

2. The range problem

Pantsir-S1 has an engagement envelope out to roughly 20 km against aircraft; Buk-M2/M3 extends further, commonly cited around 35–70 km depending on variant and target type. AARGM/HARM-class missiles have stated ranges well beyond both (AARGM is generally cited around 100+ km depending on launch conditions). So in principle, the strike aircraft can launch from outside the SAM’s engagement envelope entirely — this is the whole logic of an anti-radiation missile: force the enemy radar to choose between staying on (to keep guiding its own missiles) and getting hit, try to intercept it (but if it is a miss, it might be too late to try anything else), or going dark (and losing its eyes and guns).

3. Terrain masking during ingress

The strike aircraft’s survivability leans heavily on staying undetected as long as possible during approach by flying low, using ridgelines/valleys to break line of sight to known or suspected SAM search radars, and only climbing to acquire the emitter and get a valid missile solution at the last practical moment. This is slower and riskier than a jammer-supported package, since there’s no one degrading the SAM’s radar picture while the strike aircraft is exposed.

4. The wild weasel “pop-up and shoot”

At some point the aircraft needs enough altitude/line-of-sight to either passively detect the SAM’s radar (via RWR) or receive third-party targeting data, then fire from outside or at the edge of the SAM’s own engagement range. This is a vulnerable window, when the aircraft is exposed to radars when it is above terrain masking.

5. What happens on the SAM’s side

A competent SAM crew, especially Pantsir or Buk operators aware of ARM threats, will often shut their radar down (“go cold”) or move immediately after illuminating a target, precisely to deny the ARM a stable emitter to home on. This can be countered by modern ARM’s using GPS guidance, but doesn’t give a guaranteed kill.

Examples of modern counters

AESA radars with fine angular resolution

AESA radars use many small transmit/receive elements combined electronically, giving a much narrower, more precisely steerable beam than older mechanically-scanned or conical-scan antennas. That narrower beam and finer angular measurement let the radar separate the direct return from a low target and its ground/sea-reflected image, which older wide-beam systems couldn’t resolve apart. This largely closes off the low-altitude multipath deception that made terrain-hugging or sea-skimming an effective way to break a lock.

Frequency agility

rapidly hopping frequency changes the interference pattern the multipath reflection creates pulse to pulse, decorrelating it so it averages out over the tracking window instead of producing a stable false angle.

Adaptive SideLobe Cancellation (ASLC) / Constant False Alarm Rate (CFAR) processing

image

actively nulls energy arriving from the reflection’s angle and statistically rejects clutter-level returns, both used explicitly on systems like Type 03 Chu-SAM.

How CFAR works (easy schema).

Link to the video it’s from in

‘>Links and images to understand better some concepts if I wasn’t clear enough’

image

The objective is to electronically identify ‘noise’ and the target using complex numerical methods, and cancel the sound/jammer.

Micro-Doppler / blade-flash discrimination: The Doppler paradox of an helicopter

Is used to target helicopters mainly. Doppler works by supressing sationnary stuff to only see the targets and can work without being ‘jammed’ by scanning the whole regionnal topography. But what about a stationnary helicopter such as a hovering Mi-28NM by exemple ? Well Micro-Doppler is the Doppler effect for rotor blades, compressor faces, or propellers. Each add their own oscillating signature distinct from the fuselage’s overall closing velocity. The most exploitable form is blade-flash: brief, high-amplitude spikes generated when a rotor blade presents its broadside to the radar, recurring at a rate tied to blade count and RPM, which gives seekers a near-fingerprint for classifying rotorcraft or drones even when bulk Doppler is near zero, as with a hovering helicopter otherwise indistinguishable from ground clutter.

image

Steep terminal engagement geometry

missiles (Fox 3 especially, once on their own seeker) generally close from above or a steep dive angle rather than skimming the surface themselves, which geometrically separates direct and reflected paths far better than a shallow ground-radar look.

image

sorry for the bad meme, it’s the cleanest schema I could find to explain.

Used in air vs air in WT and IRL to get almost a 100% sure shot.

What can be found in toptier missiles ?

What I could find on modern anti-air and presence of modern counters in them
Missile AESA seeker Frequency agility ASLC/CFAR Micro-Doppler/blade-flash Steep terminal geometry
Aster-30 (Block 1NT) No: I-band active seeker Classified/unknown: seeker ECCM stated (home-on-jam), agility not named Reportedly present: clutter suppression stated (Block 1 seeker), not named CFAR/ASLC Assumed present, not sourced Classified/unknown
Chu-SAM (base Type 03) No: I-band active seeker Classified/unknown (unsourced) Classified/unknown Assumed present, not sourced Classified/unknown
Chu-SAM Kai Yes Jamming resistance stated at system level, AESA implies frequency agility Classified/unknown Assumed present, not sourced Classified/unknown
AMRAAM-ER No: I-band active seeker Classified/unknown ECCM stated, not named CFAR/ASLC Assumed present, not sourced Classified/unknown
AIM-120C-7 No: I-band active seeker Classified/unknown ECCM stated, not named CFAR/ASLC Assumed present, not sourced Classified/unknown
9M317MA (Buk-M3) No: J-band active seeker Classified/unknown Classified/unknown Assumed present, not sourced Classified/unknown
CAMM No: I-band active seeker Classified/unknown Confirmed: clutter rejection stated Assumed present, not sourced Classified/unknown
CAMM-ER No: I-band active seeker Classified/unknown Classified/unknown: not sourced in this pass Assumed present, not sourced Classified/unknown
FM-3000 No: I-band active seeker Classified/unknown Classified/unknown Assumed present, not sourced Classified/unknown
I-Derby ER No: I-band active seeker Classified/unknown: software-defined, upgradable against EW Classified/unknown Assumed present, not sourced Classified/unknown

Aster 30 has intercepted a supersonic sea-skimming target (French Navy, October 2025). The Russian MoD claims Buk-M3 intercepted simulated cruise missiles below 10 m. Approaching from above to defeat multipath is documented in the patent literature (US 6,674,390), but no missile here has a published profile

Sources

Aster-30

ASTER | MBDA
MBDA To Upgrade Aster 30 Block 1 Missile System IDEX 2025 - Eurosam promotes Advanced Aster 30 B1NT Missile and SAMPT NG - EDR Magazine
Arabel radar frequency agility: https://www.army-technology.com/projects/aster-30/
First test firing of new French-Italian ASTER 30 B1 NT surface to air missile - Naval News
October 2025 intercept of a supersonic sea-skimming target: https://armyrecognition.com/archives/archives-naval-defense/naval-news-navy-2025/french-fremm-alsace-fires-aster-30-missile-to-intercept-supersonic-sea-skimmer
https://www.globalsecurity.org/military/world/europe/aster.htm

Chu-SAM and Chu-SAM Kai

https://www.globalsecurity.org/military/world/japan/chu-sam.htm Type 03 Chu-SAM | Weaponsystems.net
AAM-4B AESA seeker (2010): AAM-4 - Wikipedia
Kai jamming resistance (system level): https://armyrecognition.com/news/army-news/2025/japan-enters-hypersonic-missile-defense-era-with-mass-production-of-type-03-chu-sam-kai
Type 03 Chū-SAM - Wikipedia
Type 03 Chū-SAM Kai (SAM-4 Kai) - JGSDF's mini Patriot: Part 2
https://w.atwiki.jp/jp-summons/pages/557.html
Japanese MoD document, checked and silent on the seeker type: https://www.mod.go.jp/j/policy/hyouka/rev_suishin/r03/pdf/r03_rontenshiryou_01.pdf

AMRAAM-ER and AIM-120C-7 (same seeker)

C-7: improved ECCM with jamming detection, upgraded seeker: https://www.designation-systems.net/dusrm/m-120.html
C-7 mechanically scanned, AIM-120D possibly AESA: Evidence Of Ukraine Using AIM-120C-8 Missiles Emerges
AMRAAM-ER uses the C-7 guidance section (forum quoting Defense News): https://www.secretprojects.co.uk/goto/post?id=458925
AMRAAM Missile | Raytheon

9M317MA (Buk-M3)

Active radar homing head (ARGSN) by Agat: 9K317M "Buk-M3" medium-range anti-aircraft missile system | Missilery.info
Moscow's Missile Shield: BUK-M3 Viking Claimed Able to Neutralize F-35s, Cruise Missiles, and Hypersonic Threats - Defence Security Asia
Buk M3 - Russian Medium Range Air Defense Missile System - смотреть видео онлайн от «Сота за Городом» в хорошем качестве, бесплатно опубликованное 8 июля 2026 года в 21:24:55 00:01:26.
https://www.globalsecurity.org/military/world/russia/sa-11-9m317.htm
Russian MoD claim about cruise missiles below 10 m: TOR and Buk air defense systems tested against incoming missiles at less than 10m altitudes - Asian Military Review

CAMM and CAMM-ER

Active RF seeker with clutter rejection: https://www.airforce-technology.com/?p=203295

CAMM CAMM-ER Sea Ceptor SAM Missile Air Defence System MBDA and CAMM (missile family) - Wikipedia
MBDA CAMM-ER / Albatros-NG Naval Air Defence System - Quwa
Low-altitude threats in the design brief: Land Ceptor ~ Success For MBDA CAMM Interceptor | Joint Forces News

FM-3000

HQ-11 - Wikipedia
https://www.globalsecurity.org/military/world/china/fm-3000.htm

###I-Derby ER
I-Derby ER, software-defined solid-state RF seeker:** PGBET - Situs Slot Terpercaya Tempatnya Spin Cuan Tanpa Drama
SPYDER - Wikipedia

Conclusion:

Visible complications of such application

Sadly, this addition would completely change the dynamic of toptier air gameplay. I’ve tried to list the arrangement to be implemented in an optic of keeping CAS possible and fair.

Keep in mind that multipathing is not the only way to escape a missile !

  • point n°0: stock chaff will be not only good but a need in smaller environements.

  • First of all, multipathing won’t work anymore after a certain missile generation (already partially in-game with SACLOS or IR missiles) , or be reduced to altitudes that messes with fuze’s sensibility, which makes pilots risking a lot with abrupt topography changes and a much higher risk of crash (that will be combined with the ‘new’ ,as of july 2026, maneuver kill mechanic.)

  • Secondly is the issue of smaller maps; some have air spawns too close and as well the end of the map still in the ‘dead’ zone of some missiles. Pilots will have to constantly notch, use the terrain and evade missiles without any possibility to have rest.

  • Helicopter will have to use as much as possible terrain coverage and MAW’s chaffs. The ‘hind doctrine’ ,as I call it, of frontal attack and count on armor/ECCM won’t be as good.

  • Helipads and airports will have to be in safer area, and more distant from the ground map. But remember that a static aircraft with shut down and cooled engine have no difference from a tree !

  • Slower gameplay, maybe a need for longer battles ?

Those changes are realistic and manageable; it is a big change in the gameplay, making pop-up attacks and short range air-to-ground missiles less common.

Links and images to understand better some concepts if I wasn't clear enough

https://www.radartutorial.eu/01.basics/Angular%20Resolution.en.html

To understand fine angular resolution.

https://www.researchgate.net/publication/313392321_Object_Discrimination_in_GMTI_Doppler_Radar_Data

image

to understand better Blade Flash discrimination

https://www.youtube.com/watch?v=BEg29UuZk6c

Constant false alarm rate - Wikipedia

To understand better CFAR (Constant False Alarm Rate)

What is Adaptive Sidelobe Canceller? | RF Essentials

To understand ASLC better (here in a context of electronic jamming)

Thank you for taking time to try to understand such complex systems ! I might even myself don’t understand fully things; feel free to correct me on those.

The objective here is not in an optic of complexification of mechanics, but to show a software and hardware update having as goal the rejection of multipathing and low-altitude tracking.

PS: This will surely not be added soon. Better missiles and jets can be added, ECM as well, and maybe modern stealth airframe will help a lot for HARM missions.

Give your opinion about changing multipathing for last-gen missiles

  • Change multipathing for toptier ARH SAM if sources/proof shows it can counter multipath.
  • Change multipathing for every aunti-air missiles (air-to-air as well) if sources/proof shows it can counter multipath.
  • No, keep multipathing as a way to deal with some of the modern missiles.
0 voters
10 Likes

I think for the sake of the game being playable above certain BRs an unrealistic degree of multipathing is needed. Imagine if we couldnt multipath to get away from hawk missiles in NE, that would be actual hell to play, now imagine its a quad of F-14s or any fox-3 slinger all looking at YOU, theres no fun in knowing you will die and you cant stop it unless we get some really good ECM and decoys soon. I think some tweaks to your idea would make it far better for gameplay.

Make trees affect radar altitude, they dont at the moment so on maps with absurdly giant trees you cant multipath to escape even relatively crappy radars without risking eating the local flora. This is especially annoying dealing with SAMs that can follow you through a forest which should be impossible. It also fixes your concern about helipads and airstrips if theres woodland or more hills giving natural radar cover.

Having a flat 50m ( i think its 50m, i always stick to 40m as the mpath and IOG can get lucky still) for all radar is rather silly. I think it should have differing heights depending on a general radar “generation”, earlier worse radars having a higher mpath alt (would also help with the dominance of the F3H right now) while the newest AESA radars have a much smaller Mpath height would help with the games authentic feeling.

TLDR:

I think multipath is a neccessary evil in the quest for realistic representation but the game can handle it better (trees affect Radar Altitude) and different alts for Mpath on newer better radars.

4 Likes

Good post however its complex would be a realistic addition esspecally for the future of the game for example when we get missile ships dumping SAM missiles into a sea skimming aircraft or missile for them to all miss when why should not have would be annoying. +1

True ground skimming is how I limp around at top tier.

3 Likes

you will almost never not see me flying like this as soon as phantoms start appearing:
image

4 Likes

We need altitude hold and terrain following systems if available to the plane. (Terrain following tech was developed for this very issue)

1 Like

I dont think ground following autopilot would be good for the game tbh. let us follow the ground with radar sure, but i dont think automation should appear at all

4 Likes

If the Automation was built into the plane (I should write a suggestion for it) it should have it for example the BAC TSR-2 had the tech built in to go low and fast. Some systems to my knowledge can only work on the sea.

kinda makes the game play itself tho. WT has had serious issues with botting in the past (there was a while where almose every wyvern was a bot doing AFK grinding) and i dont think that should be incentivised.

This is getting off topic now, Worth suggesting it though as im sure aspects of it can work

2 Likes

See, possibly for SAMs it could be a balancing thing. But, people should be warned that for AAMs that means multipath altitude for R-27 and R-77s would be 20m, well within the splash zone.

To add to this:
Multipath is something I use less than 1% of the time, but it as a feature allows for more varied enemies for both teams.
Many at high altitude, mid altitude, & the deck.

It’s far more interesting than matches all on the deck or all up high.

I enjoy the variety of matches.

This one is funny, I just wanted to point it out.

1 Like

Only and only onces chaff is stock, I don’t think ECM would be stock but chaff does need to be stock for this

+1

1 Like

Wow torturing helis even more, i never used top tier spaa, before update i had only stupid chaparral almost to top of top tier.

i mean the arh spaa suck hot ass against helis so no.

Keep multipathing overall, but nerf it.
Make it so it can’t be used as your main method of avoiding most Fox-3s launches like you still can do.
It’s still possible to expect a missile to miss even at top tier air rb by just sitting <60m ralt

1 Like

Until they reduce team sizes to 6-8 maximum multipath needs to stay as is. If you nerf multipath/remove it with current team and map sizes you are looking at complete colapse of ARB.
Also considering what playerbase Gaijin caters to I’m confident multipath and team sizes will stay as is.

Reduce team sizes
Reduce max Fox-3 counts (down to 8)
Make notching a bit harder
Nerf mp
Make chaff stock

Introduce mandatory guides or tutorials for reaching each tier of missiles to defend against and use said missile

That’s what I want really

5 Likes

caption.3abd1be1

1 Like

i think missiles are more limited by the possibility of their proxy fuse getting set off by the ground rather than getting multipathed.
R-40 for example (50m instead of 20m because it has a larger proxy range)

1 Like