already reported This Seems Wrong (Aim-120C Spoofed By Small Amount of Chaff Along With Notch)

[D4n]

Shouldn't ED also finally add the realistic logic that as soon as a radar-missile gets super close to chaff, that that finally causes the missile's fuze to explode? I've been waiting for it since years now!

Edited May 6, 2022 by D4n

[nighthawk2174]

6 hours ago, D4n said:

Shouldn't ED also finally add the realistic logic that as soon as a radar-missile gets super close to chaff, that that finally causes the missile's fuze to explode? I've been waiting for it since years now!

 

depends on the fuze, if the seeker is IR/laser based it shouldn't do anything.  Most modern missiles have a doppler based radio fuze which should prevent this if the chaff has already stopped..  Older systems like the SA2 sure. 

[D4n]

16 hours ago, nighthawk2174 said:

depends on the fuze, if the seeker is IR/laser based it shouldn't do anything.  Most modern missiles have a doppler based radio fuze which should prevent this if the chaff has already stopped..  Older systems like the SA2 sure. 

if the chaff "stopped" ? An old SA2 system has a feature that would not make it explode when it gets very close to chaff, you're saying?

[nighthawk2174]

2 hours ago, D4n said:

if the chaff "stopped" ? An old SA2 system has a feature that would not make it explode when it gets very close to chaff, you're saying?

As far as I'm aware modern missiles fuzes use the Doppler shift of the target to filter out clutter.  The older fuzes on the SA2 I believe were just simple radio proximity fuzes that went off when a return above a certain threshold was detected.  This is part of the reason for their inability to hit low flying targets.

[D4n]

Doppler shift shouldn't be detectable though if most radar waves are redirected by the loads of chaff that is "blocking" the LOS to the target, or?

[nighthawk2174]

46 minutes ago, D4n said:

Doppler shift shouldn't be detectable though if most radar waves are redirected by the loads of chaff that is "blocking" the LOS to the target, or?

Chaff is not a mirror, its far more appropriate to view it like a cloud.  And like a cloud sunlight still gets through, the intensity will be reduced but most certainly not reduced to nothing.

Edited May 7, 2022 by nighthawk2174

[KlarSnow]

Doppler and pulse doppler radars do not have issues seeing through chaff, it does not block or interfere or reduce detection ranges with tracking or search modes. It may show up as a false target, briefly (depending on wind and how quickly it blooms) but it does not screen or block anything to a doppler or Pulse doppler radar.

 

From the openly available "Electronic Warfare Fundamentals" book.

Edited May 8, 2022 by KlarSnow

[D4n]

Wow very interesting, thanks guys! So now the only question remains is whether AIM-120B's proximity fuze would detonate the warhead if it passes very closely to a cloud of chaff.

Edited May 8, 2022 by D4n

[nighthawk2174]

3 hours ago, D4n said:

Wow very interesting, thanks guys! So now the only question remains is whether AIM-120B's proximity fuze would detonate the warhead if it passes very closely to a cloud of chaff.

 

As far as i'm aware its a doppler based fuze.  So it should largely ignore chaff and ground clutter, there will be edge cases where the chaff is still fast enough to trigger the fuze.  However for now there are far bigger fish to fry in terms of fixing things.

[D4n]

On 5/8/2022 at 4:03 PM, nighthawk2174 said:

As far as i'm aware its a doppler based fuze.  So it should largely ignore chaff and ground clutter, there will be edge cases where the chaff is still fast enough to trigger the fuze.  However for now there are far bigger fish to fry in terms of fixing things.

Wow okay

[nighthawk2174]

On 5/7/2022 at 6:06 PM, KlarSnow said:

Doppler and pulse doppler radars do not have issues seeing through chaff, it does not block or interfere or reduce detection ranges with tracking or search modes. It may show up as a false target, briefly (depending on wind and how quickly it blooms) but it does not screen or block anything to a doppler or Pulse doppler radar.

 

From the openly available "Electronic Warfare Fundamentals" book.

 

Something though that should be mentioned is in the beam the targets RCS will also explode.  It's often orders of magnitude higher then frontally.  Which would reduce the chaff to target signal ratio.  But it would mean more time between the chaff becoming a larger target then the aircraft as it takes time for chaff to bloom.

[KlarSnow]

The other thing is chaff that is employed straight and level should be far less effective than chaff employed while maneuvering. This is due to several reasons. First while the target is changing parameters and not in a steady state, the likelihood of the tracking or coasting mechanism biting off on a false target is higher. Second, bloom rate. In level nonmaneuvering flight regardless of aspect, chaff does not bloom very quickly. It must bloom inside res cell of the threat radar to be an effect. In maneuvering flight, wingtip vortices and other turbulence from the maneuvering jet disperses the chaff bundle and helps it bloom much quicker.

 

Essentially if you turn to the notch and just sit there pumping chaff, it should be very ineffective for all the reasons mentioned.

However if you dispense chaff as you are maneuvering aggressively into or out of the notch, that should be more effective. 

Overall the biggest issue with chaff is the interaction in the game is in the wrong place to feel like a good mechanic.

If you want an example of this. Radars on fighters can detect launched AAM's:  a small RCS target that they are not really designed to detect that should in most cases be below the noise floor of what they are trying to detect or track.

Radars however cannot detect or display false targets from chaff at all : a large RCS decoy specifically made to try and decoy radars and radar operators...

 

Incoming AAM's should be very minimally affected by chaff in most situations relative SnR is so much higher for any missile due to how close it is to the target, and their range and angle gates are going to be much smaller, just due again to how close and how rapidly they are approaching the targets. Host supporting radars however have a much more even SnR and due to the range they are at will have a much wider azimuth cell. This is where chaff should be effective, at pulling supporting radars off the target, not randomly making missiles just stop guiding while the supporting radar still has a good lock/track.

This should apply to just about every missile in the game SARH or ARH

Edited May 14, 2022 by KlarSnow