A method of GPS accuracy adjustment for an integrated INS/GPS navigation
system which utilizes microelectro mechanical systems (MEMS) based
inertial sensors to mitigate multipath problems arising when a vehicle is
in an area with many high-rise buildings is disclosed. Even when GPS
measurement output values are deviated from that expected, the INS/GPS
navigation system uses as many measurement outliers as possible without
discarding, unless they are obvious error values, thereby maintaining a
practical level of accuracy. The measurement outliers typically occur
when the integrated INS/GPS navigation system receives GPS signals which
have transmitted through multipaths such as reflection by buildings,
since the signal path lengths vary.