Abstract: For the ship-borne 3D phased array radar,in order to realize airspace coverage in geodesic coordinates and stable tracking of targets,moving platform compensation is required to achieve correction for beam direction.During beam correction,the error from ship attitude information will be also included in radar measurement errors so as to affect accuracy of radar measurement.Only if the mechanism of error correlation is analyzed thoroughly,then is it possible to effectively isolate error sources and correctly evaluate radar performance while output data of radar occurs sudden change.