Slave radar vs flares

Hi guys, I have an issues to confirm:
For example: me flying F15 with 9M vs J39 that is spamming flare periodically at 1s interval.

  • If I locked him with my radar then use the slaving 9M, will the seeker, when launched, track the latest flare or the J39?

it’ll “track” both and choose the hotter one which may be the flare depending on when exactly you shot it

that is true for most IR missiles, 9M is different. it does not track hottest, it tracks only jet BUT if it detects flares it will stop tracking for a short time and then start tracking again to avoid locking the flare.

Radar with IR missiles is ONLY before launch, after launch the missile will act like IR missile, the 9M specifically has IRCCM in the form of short periods of non tracking if a flare is detected.

tell me how does 9M know it’s a Jet and not a flare?

Only if it successfully locks onto the jets heat signature before.
In which case, if it encounters multiple heat signatures, it will suspend active IR tracking and resort to IOG tracking for a short period of time until the heat signature exits the seekers FOV.

so if you pre-flare the 9M may not lock the jet but rather the flare or nothing at all

Affirmative.
Just like any other IR AAM.