Uh gambit.. would not the newer generation IR seekers that pick up the heat at the leading edges and in some cases the complete airframe itself..ala.. Python 5...or 9x..negate the IR suppression advantage??
Yes...That is correct. However, infrared sources such as leading edges from a complex body do not provide the seeker as much 'localization' of an IR source as the engines do. Seekers are programmed to focus on a body's highest concentration of IR emissions. The body itself provides the background contrast for the engines. In the case of a frontal view, leading edge IR emissions depends on the aircraft's speed, the higher the greater, and if there are insufficient contrast between the leading edges and the aircraft's fuselage, or even against background, above a certain threshold, then there is insufficient 'localization' for the seeker.
There is a complex relationship between array dimension, the amount of IR sensors in an array, and the ratio of activated sensors versus inactive sensors. The total amount of sensors
DO NOT determine array dimension. A lot people confuse the two items. It is the spacing between individual sensors that determine array dimension. Sensor technology is a major factor, of course. The more sensors we pack inside an area, the greater the ratio between activated sensors versus inactive ones we can have when we come up on an IR source, which lead us to -- fusing distance.
Fusing distance is the range between the missile and the target when the missile detonate. The closer the detonation the greater the damages to the target. Say we have 100 IR sensors in an array. In one situation, we have 50 activated sensors but there is no 'localization' of these activated ones. In another situation, we have only 30 activated sensors but they are highly concentrated in a corner of the array. We then program the flight controls to accept guidance commands to turn the missile so that these 30 activated sensors begin to 'move' across the array until this 'localization' is centered. As the missile approaches the target, we expect to have an increase of activated sensors versus inactive ones. Once this ratio crossed a certain threshold, we detonate and this is the fusing distance. We have to expect the target to maneuver. As the target maneuvers, it is possible that the amount of activated sensors can decrease or increase inside a time frame. So inside this time frame, what is the ratio between activated sensors versus inactive ones
AND the rate of changes that we are willing to tolerate before we could lose the target?
So for leading edge IR detection, we do not have as localized IR sources as the engines do across the array. Not only that, they are not as strong as the engines. The activated sensors, or pixels, are spread out across the array. As the target maneuver, we will have x-y changes and rate of changes for activated pixels compared to inactive ones. What is the threshold for loss of activated pixels, and we have to expect there will be losses compared to the constancy of the engines, before we alert the pilot that we have an IR lock? Remember the fusing distance criteria.