[SEMI-FIXED] GBU-32 JDAM speed issue

[bpstalker]

JDAM's have an issue under the current build. Their ground speed is heavily dropping after release (down to 1 kts before impact) while the TAS stays at 530 kts. So the Korean MIG-23s can easily kill them with their APEXs, Archers or guns in the Korean missile crisis scenario.

By the way is it realistic to shoot down bombs with IR missiles? (what heat the sensor can lock on?)

[Dimitris]

1. The gradual reduction of ground speed is realistic (pitch-down attitude).

2. Can you post a pre-engagement save of the above? Thanks.

3. Modern IR seekers can home on even relatively cool surfaces, they don't need a blazing exhaust/afterburner trail like the older ones. What _is_ strange is that a small warhead should have a reduced ability to deflect a guided bomb weapon. Again a save would help.

Thanks.

[bpstalker]

Thanks Sunburn. My comments below

ORIGINAL: Sunburn

1. The gradual reduction of ground speed is realistic (pitch-down attitude).

GBU-12s don't slow down. They keep their horizontal speed till impact. Is this only applies to GBU-32 JDAM?

2. Can you post a pre-engagement save of the above? Thanks.

Added both Missile crisis and a test scenario. In Korean missile crisis, I have a save where the weapons are just released against IWON AB (N40°11'01" E128°50'34") In this game the Mig23's were able to circle around the bombs and reattack

3. Modern IR seekers can home on even relatively cool surfaces, they don't need a blazing exhaust/afterburner trail like the older ones. What _is_ strange is that a small warhead should have a reduced ability to deflect a guided bomb weapon. Again a save would help.

Ok I didn't knew that. Thanks for explanation

Thanks.
[/quote]

[Dimitris]

Thanks, logged and it will be investigated.

[Dimitris]

Okay, there are three inter-related factors at work:

1) Guided weapons had somewhat excessive sensor signatures, because we used the wingspan as the main reference dimensions for auto-calculating them. In DBv499+ we switched to using the body diameter as the reference value instead. This is especially important for glide/winged weapons like the SDB.
The reduced signature has two significant effects:
(a) It reduces the range at which the weapons are detected, and combined with the revised OODA values this results is a vastly reduced reaction window.
(b) The reduced signatures also make it harder to actually engage those weapons, both from surface-to-air defences and also by airborne fighters.
Note that you have to migrate any scenario of interest to a v499+ DB in order to observe this.

2) IRL ballistic weapons like JDAMs (and LGBs, and plain iron bombs for that matter) rapidly accelerate on their dive, often reaching supersonic speed if released from med/high altitude. This provides airborne interceptors with a very limited time window to get in position and engage them. Currently this is not modelled because we use constant climb/dive rates for A2G weapons (something more appropriate for constantly-powered guided missiles), however we do plan to soon introduce the boost-coast mechanics also to A2G weapons, which will remove this issue.

3) Because of #2, the falling bombs pass from any interceptor's FOV at a rapidly crossing rate, and most AAW weapons have very real limitations on the max target tracking rate that they can engage. This is on our radar and we intend to introduce it as yet one more wrinkle in the pre-fire checklist.

Marking this as semi-fixed, until we can sort out factors #2 and #3.

[blu3s]

Awesome, thank you!

Are there plans to tweak RCS for other types of weapons?

[Dimitris]

Awesome, thank you!

Are there plans to tweak RCS for other types of weapons?

What other types?

[blu3s]

What other types?

Sorry, I misunderstood you, I thought that only JDAMs are going to be recalculated.

[KungPao]

Okay, there are three inter-related factors at work:

1) Guided weapons had somewhat excessive sensor signatures, because we used the wingspan as the main reference dimensions for auto-calculating them. In DBv499+ we switched to using the body diameter as the reference value instead. This is especially important for glide/winged weapons like the SDB.
The reduced signature has two significant effects:
(a) It reduces the range at which the weapons are detected, and combined with the revised OODA values this results is a vastly reduced reaction window.
(b) The reduced signatures also make it harder to actually engage those weapons, both from surface-to-air defences and also by airborne fighters.
Note that you have to migrate any scenario of interest to a v499+ DB in order to observe this.

The current DB in 1319.1 is DBv499, does that mean the signature issue have been fixed?

thank you

[Dimitris]

Yes.