A new approach that minimizes the total active laser target designation time is proposed for guidance of laser guided weapons.The laser guided weapons can make full use of INS/GPS guidance and estimate the error of the weapon-to-target vector by covariance information within a Kalman filtering.At any time the missile needs to be sure that it can navigate to any point within the area around the target that is described by this covariance.Therefore at each moment during the flight there exists a covariance threshold above which the weapon cannot guarantee its ability to navigate to the target.In our proposed approach when the threshold is exceeded the weapon requests a brief laser designation of the target.The laser designation provides an accurate measurement of the bearing of the target with respect to the missile and this is used to improve the estimation of the weapon-to-target vector.In turn this can be fed back into the Kalman filter to improve the internal state estimation.The approach can minimite the laser designation time while guaranteeing the attacking precision.