IR Missile lock ranges on cold maps

Machinery of War Discussion Ground Vehicle
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1

I’ve been playing the Stormer AD a lot recently finishing the stock grind and i’ve noticed something… wierd…

The lock ranges are notably lower on cold weather maps and much higher on hot maps.

Is this not reversed?

From my understanding, cold weather conditions should help cool the seeker further improving its performance AND increase the contrast from the targets heat signature. Meaning that on a cold map, you should actually see an increase in seeker performance and not a decrease.

Before I put the work into testing and ultimately writing a bug report for this, I just wanted to see if my understanding of IR seekers was correct and if anyone had some primary sources docs usable for a bug report.

Initial testing.

Recon drones are about 0.6km on cold maps but 1.3km on hot maps

Helis can be as much as 4-5km quite happily on a hot map but i’ve just hand a heli I couldnt lock onto at 2.2km on a cold map

3 Likes
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We probs should bug report this, hmu if you need help with targets to lock on maps for screenshots

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Yeah, and I will definetly take you up on that but just wanted to

  1. confirm that we are correct in our theory

  2. ideally have a primary source confirming for the bug report

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I know its right, i cant lock helis until they are in top of me on snow maps but can cross map them at times on deserts.

Pretty sure basic logic is enough for this report

5

This is Gaijin we are talking about…

6

yea true. and the CBR mods (that we havent spoken to on discord) can be problematic

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Cold weather will also cool down targets and hot weather will increase a targets temperature

The weather cooling down the seeker is pretty much a non factor with all aspect seekers that are already cooled by liquid nitrogen or something of the sorts

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Yes, however a cold environment should provide better contrast between the target and the surrounding, increasing lock range.

IR missiles don’t magically stop working above 40,000ft, where it is far colder than almost anywhere at sea level, ever.

9

The way I understand it, IR signature ingame is simply proportional to engine thrust times a constant for specific planes (which by itself is very wrong, and overly favours small planes), but if you verify lower detection range in colder maps then it’s either overcorrecting for air density, or it’s adjusting peak exhaust temperature proportionally to ambient temperature without considering temperature contrast.

By any chance, does anybody notice IR detection ranges improving a lot with altitude as they should? Like for example, based on the graph below you’d expect a rear aspect missile/IRST to have about 1,6 times the detection range at 40 000 feet compared to sea level.

Aim-4c - GAR-2A gimbal limits
Aim-4c - GAR-2A gimbal limits1157×778 209 KB

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For the sake of reference, If I had to decide on a formula for rear aspect heat emmited per plane it would be something like: reference value x Thrust specific fuel consumption (the more efficient, the lower the exhaust gas temperature) x √ thrust (because an engine that has 4 times as much thrust isn’t 4 times as visible as the game currently assumes, as in order to have 4 times the intake area it only has to be twice as big) / [1+bypass ratio] (adjusts for modern turbofans, and can also quantify exhaust dilution used in stealth aircraft like the f-117).

I also don’t know the exact formula used to calculate all aspect heat emissions, but i do know that it should have a modifier for when target aircraft reach the speed of sound and beyond, like shown in this table.
ir detection range vs speed

Since many irst manufacturers advertise their all aspect detection capability by quoting supersonic targets, you could also use this table to estimate IRST all aspect tracking range for subsonic targets…