SEEKER BORESIGHT ERRORS CAUSED BY RADOME REFRACTION ARE OF CONCERN IN RADAR GUIDED MISSILES BECAUSE THEY PRODUCE UNWANTED FEEDBACKS IN THE HOMING SYSTEM AND COULD LEAD TO PERFORMANCE DEGRADATION OR EVEN INSTABILITY.

SEEKER BORESIGHT ERRORS CAUSED BY RADOME REFRACTION ARE OF CONCERN IN RADAR GUIDED MISSILES BECAUSE THEY PRODUCE UNWANTED FEEDBACKS IN THE HOMING SYSTEM AND COULD LEAD TO PERFORMANCE DEGRADATION OR EVEN INSTABILITY. CURRENTLY USED COMPENSATION TECHNIQUES - RADOME TAILORING AND ERROR MAPPING - ARE EXPENSIVE, TIME CONSUMING, LIMITED IN APPLICATION TO NARROWBAND SYSTEMS, AND CANNOT ACCOUNT FOR IN-FLIGHT VARIATIONS DUE TO HEATING, ABLATION, ETC. SPARTA PROPOSES TO DEVELOP A TECHNIQUE FOR REAL-TIME ESTIMATION AND COMPENSATION OF RADOME ERRORS. A CAREFULLY DESIGNED SINUSOIDAL STIMULUS IS INJECTED INTO THE HOMING LOOP AND RADOME ERROR SLOPES ARE ESTIMATED FROM THE RESULTING OSCILLATIONS IN THE MEASURED BORESIGHT ERRORS. THE COMPENSATION SIGNAL IS GENERATED FROM THIS ESTIMATE AND APPLIED TO THE SEEKER TRACK LOOP. SINCE THE PROPOSED TECHNIQUE ESTIMATES RADOME ERRORS IN REAL-TIME, THE COMPENSATION SCHEME IS ADAPTIVE TO VARIATIONS IN RADOME ERRORS. COMPUTER SIMULATION OF A HOMING SYSTEM WILL BE UTILIZED TO EVALUATE THE PERFORMANCE OF THE PROPOSED ESTIMATION AND COMPENSATION SCHEMES, AND TO STUDY THE SENSITIVITY OF THE PERFORMANCE TO VARIOUS PARAMETERS.