A SAR monopulse and inverse monopulse weapon guidance system (10) for guiding a weapon (13) to a target (15) comprises a launch platform (11) and a synthetic aperture radar (12) disposed on the launch platform (11) for generating a synthetic aperture radar monopulse map of an area surrounding the target (15), for designating the location of the target (15), and for transmitting an inverse monopulse illumination that comprises a sequence of alternating sum and simultaneous azimuth and elevation difference patterns centered on the target (15). The weapon (13) comprises a weapon guidance system and noncoherent radar seeker (14) that is responsive to guidance commands transmitted by the launch platform (11), for receiving reflections of the alternating sum and combined azimuth and elevation difference pattern from the target (15), and for using these reflections to acquire and track the azimuth and elevation difference pattern null on the target (15) so as to fly an optimum trajectory to the target (15) (Fig. 1). A respective method for guiding the weapon (13) to the target (15) is also disclosed.