NAVIGATION SYSTEM

PURPOSE:To remove an error between an absolute azimuth and a detected azimuth and thereby to improve the precision, by correcting a plurality of mean values of the X and Y components of an azimuth sensor respectively in accordance with the magnetization characteristic of a vehicle. CONSTITUTION:After a destination is set by operating a switch of an operating switch unit, an ON-OFF pulse is generated from a vehicle-speed pulse sensor 3 in accordance with the running of an automobile, and every time when this pulse turns ON, an interrupt signal is inputted to MPU19 through an interface 24 and an input-output LSI22. Synchronously with the input timing of this signal the execution of a distance interrupt program is started. When it is determined that the data from an azimuth sensor 2 are sampled in (n) times, the data stored in RAM21 are multiplied by 1/4 so as to compute the mean value of the data in the number of (n). Then, an operation for correcting the azimuth data is conducted on the basis of an operation formula stored in ROM20. Next, the advancing direction of the automobile is calculated from the relationship between the X and Y components of the azimuth data on the basis of the operation formula of ROM20 and the data on the azimuth.