Dear dong, the pixhawk has low cost sensors as mpu6050 but that is so good in real flight, they are using EKF with 22 - 24 states with a GPS , would you mind tell me what is different between pixhawk and your 16 states EKF?
I know nav420 (crossbow) has two EKF, 7 and 13 states. is kind of sensors important for optimal result?
Best Regards
Amin