Modern infrared missiles, like the AIM-9 Sidewinder, have a more advanced guidance system. Supercooled infrared detectors help the missile find a possible exhaust source, and software assists the missile in flying towards its target. Pilots normally drop flares to confuse or decoy these missiles by creating more multiple heat signatures hotter than that of the aircraft for the missile to lock onto and guide away from the defending aircraft.
Radar homing missiles could sometimes be confused by surface objects or geographical features causing clutter for the guidance system of either the missile or ground station guiding it. Chaff is another option in the case that the aircraft is too high up to use geographical obstructions. Pilots have to be aware of the potential threats and learn to distinguish between the two where possible. They used the RWR (radar warning receiver) to discern the types of signals hitting their aircraft.