iir seeker has a limitation itself 25-35km range,it seems range is short but its seeker passive and most dangerous,rf seeker is active and upon to counter measures but range is becoming good,ı think what we see on hisar -o systems,two types of missiles in same battery with iir or rf seeker,so ı think its very clever strategy....if the target is within the limit of the iir seeker with smokeless missile its almost dead,if its not you can use rf seeker missile but targets missiile warning system can detect the missile is coming
Besides, Clear skies on relatively high temperature regions such as Central Anatolia are convenient to IIR seeker. Rainy, Foggy, Misty weather conditions such as East Black-Sea affect the detecting range/visibility of seeker robustly at terminal phase. The best sensor performing better results are LWIR in Category-1 and 2 class fog and IIR seeker head with LWIR detectors can't perform anything better than the performance of a naked eye in Category-3 so Active RF seeker is better on longer ranges without being effected by wheather conditions but open more to be jammed/detected by enemy sensors.
Here is the results of detection range (km) performance of different bandwith (Naked Eye, MWIR, LWIR) IIR seekers in a condition of a 10 degree temperature differences between ground and target location. As It is seen, The naked eye performs better than any sensor in category-III heavy foggy condition, because heavy fog clouds can't be penetrated by thermal radiations . In Category-II, LWIR is 4x superior to MWIR.
Rain can significantly reduce target contrast on IIR sights and LWIR or MWIR perform similarly in the presence of rain. Range on rainy weather is a dramatic drop off in the 100-500 meter range.
Category I: visual range 1220 meters
Category II: visual range 610 meters
Category IIIa: visual range 305 meters
Category IIIc: visual range 92 meters
so Combination of both sensor on a deadly medium range national missile system inside of same launchers will make a big surprize to enemy assets supposing to benefit the atmospheric conditions in favour of own interests to reach their targets.
Hisar-O RF Seeker Head
The best IIR solution from Aselsan. Dual-Band