The popular measuring sensors have some shortcomings

but fluxgate sensor compensates these

and it is applied to measure course and pose angle in vehicle navigation system. There are two ways that are put forward to solve the questions in course of using

the one is the vertical-function minimum two-multiply fitting criterion to eliminate the influence of vehicle magnetic field

the second is Kalman filter to compensate the observation error

which improve the precision effectively. At last

the maximal error is only 0.74°

the two ways are feasible and the ending is satisfied through validating by experiment.