I can find no reference to any system employed for the detection or interrogation of IR lamps in any of my books or on the WWW on this subject (Including "Most secret war" by RV Jones) and wonder if the existence of the system has been forgotten over time, perhaps due to the sensitive classification of such a device, or if these lamps were simply some form of low intensity formation lamp and unremarkable in their use.
Don't quote me but
AFAIK IR gear first appeared in the Vietnam war.