reported earlier IFF inconsistencies and TALD

[Ahmed]

Hi,

In the past a design decision was taken by the team to interpret that an IFF Interrogation by two different aircraft without a positive friendly response means hostile. This is fully inconsistent with how real IFF works, where this would just mean a LoF (lack of friendly) indication, and it could very well be a friendly aircraft with the wrong codes/crypto loaded or the IFF bent.

This is now exacerbated by the fact that, since the introduction of TALD, TALD will correctly show as unknown while the hostile launching aircraft will show as hostile due to lack of friendly IFF response, as shown in the attached track.

IFF should only be able to positively identify friendly aircraft. A hostile declaration should require more criteria than just a lack of IFF response. In the attached track note that the launching aircraft is tagged hostile out of "NCTR range" and without any surveillance tracks.

In an ideal world there would be a mission scripting API and/or ME IFF profile option to specify the hostile declaration criteria and to interact with the system.

This is just one of the many incongruences that the current IFF implementation has in the F/A-18/F-16 (such as aircraft without any kind of M1/2/3/4 transponder being able to respond to interrogations, or neutral aircraft showing as hostile, among others).

tald_iff.trk

[Ahmed]

Just a quick quote from CNATRA on the matter (P-881, cleared for public release):

Quote

IFF requires a cooperative target (i.e., one with the ability to respond to interrogations). IFF can positively identify and authenticate friendly targets and provide the Mode 3C requirements to complete a commercial air or civil air profile, but it can’t locate adversaries. If an IFF interrogation receives no reply or an invalid reply, the object cannot be identified as friendly, nor can it be positively identified as a foe with 100% certainty. In other words: IFF won’t tell you who the adversaries are, but it will tell you who they aren’t providing friendlies and commercial/civilian aircraft all have functioning IFF transponders.

 

[BIGNEWY]

I have added the comments to my already open report. 

thank you