Abstract: The signal received by the missile seeker is processed in the monopulse receiver to determine the direction (bearing and elevation) of the target. The sum and difference voltages generated by the signal are electronically manipulated to obtain the boresight error (angle) to the missile seeker. This angle is processed to provide appropriate guidance to the missile. In the presence of multipath in sea environment, this signal is a combination of the direct target return and a return seemingly emanating from the target image beneath the sea surface. This concept of multipath is utilized in terrain bounce jamming to jam the missile seeker. This paper focuses on the study of the effect of terrain bounce jamming on missile guidance based on analysing the boresight error to the missile seeker.