Loss-of-Lock Assessment (LOLA) for Indication of Countermeasure Effectiveness

Countermeasures (CM) to defend aircraft against missile attack function by disabling or deceiving the missile guidance system. This "soft kill" is not immediately apparent to the aircraft crew, who may continue to expend attentino and CM assets against a missile that is no longer threatening. The combat survivability and effectiveness of military aircraft would be enhanced by an automated system capable of rapidly and reliably assessing the threat status of an attacking missile. In the proposed Phase I, PRA will explore several related methods for providing this capability. Specifically, track-estimation algorithms operating on the line-of-sight direction from an aircraft-mounted sensor to the missile will be designed and tested using a flight simulation code such as DISAMS, ESAMS or ALIA. Evaluation criteria will include the time elapsed between loss of missile lock (LOL) and the detection of same by the algorithm, and the rate of false LOL indications. The effoects of noise and measurment errors will be included. Two extensions of this concept will be explored: an active tracker providing range and angle data, and exploitation of the relation between the missile rotational microdynamics and its time-dependent radiometric signature.