Mismatching points are inevitable in scene matching because of the complexity of the matching conditions. In order to improve the reliability of scene matching guidance system

it is necessary to develop the methods of automatic recognition and elimination of the mismatching points. Due to the limitations of the aircraft maneuverability

the flight paths are rather smooth

and sometimes are linear

especially during the process of scene matching. So the relationships among the correct matching points in one matching area are regular. Three algorithms are developed according to the changing regulation of the fitting curve of matching points. The three algorithms are as follows: (1) on the basis of small curvature of the fitting curve of the matching points; (2) on the basis of the linear curve generated by the matching points; (3) taking advantage of the accuracy of the distance-measurement accuracy of INS in short period of time. These three algorithms are tested by the data gained in flight-test

and the results show that

all of the three algorithms can distinguish and eliminate the mismatching points effectively and can meet the need of real-time ability of the matching system

though the real-time ability

adaptability and reliability are somewhat different. The proper algorithm should be selected according to the practice conditions in flight

and algorithms (1) and (3) or algorithms (2) and (3) can be fused according to the matching conditions to improve the eliminating trustability of the mismatching points.