Probable SAM Launch Point
Crash Site (6:18 TT)
Area of Probable Impact End of Transponder Data (6:15 TT) Perceived Target SAM Operator
Imam Khomeini International Airport
Flight Path Estimated Flight Path Approximate Crash Site
Figure 12: Flight trajectory of Flight PS752 and reported misalignment
Operator Action # 2 – Identification of Flight PS752 as a Hostile Target According to missile system experts, such a misalignment should have had no effect on the operator’s perception of vertical movement of the aircraft or its airspeed (i.e. an airplane climbing versus an incoming cruise missile). It simply would have made the aircraft look like it was coming from another direction to the operator (i.e. southwest versus southeast). The method and precision of the altitude indication system on the SA-15 unit that shot down Flight PS752 is unknown but could have influenced the operator’s ability to differentiate between ascending, level, and descending aircraft. Iran has provided no information to describe if or how these factors were considered as part of the SAM operator’s target identification process. Figure 13 shows a typical radar display from a SAM unit. It includes radar “sweeps” across the area that it is facing; as it rotates, the sweep is displayed on the operator’s screen and revolves in sync with the radar’s scan. Through the system’s parameters and algorithms, objects that the radar detects (called “contacts”) will be identified as a target on the operator’s display when very specific criteria are met. When the Identification Friend-or-Foe (IFF) system interrogates a radar contact, it is displayed on the screen. In this case, its status is unknown as it has not yet been determined as a hostile or friendly contact. Military experts indicated the primary operator screen for such radar systems typically only display an icon for unidentified objects. While radars are often able to report the strength of the return that could provide some indication of relative target size, it is uncertain how accessible or useful this information would have been to the operator of this system to differentiate an airliner from a cruise missile. Iran has provided no information to clarify these considerations or explain how the SAM operator identified and classified Flight PS752 as a threat.
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