Abstract: A method of which uses the measured information from onboard laser detectors and GPS to resolve the roll angle of semi-active laser terminal correction projectile is proposed. A formula to calculate the roll angle is deduced by comparing the real target imaging point on imaging planeof laser detector with the calculated target imaging point on non-roll imaging plane.The effects of measured errors of projectile position, projectile velocity and laser detector on the resolving accuracy of roll angle at different quadrant elevation angles are analyzed through the Monte-Carlo simulation. The simulated results show that the maximum error of roll angle is resolved to be less than 4° by the proposed method; the measured error of laser detector has the greatest effect on the resolving accuracy of roll angle among the 3 error sources.The proposed resolving method meets the accuracy and real-time requirements, and is suitable for solving the roll angle of semi-active laser terminal correction projectile with low rolling.

Key words: ordnance science and technology, semi-activelaser guidance, laser detector, terminal correctionprojectile, roll angle resolving