| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately calculate a direction of geomagnetism on the occurrence of soft-iron effect. <P>SOLUTION: A device 1 comprises a component for generating an internal magnetic field Bi and a magnetization magnetic field Bm, a three-dimensional magnetic sensor 60, and a CPU 10. The CPU 10 calculates, assuming that coordinates indicated by a plurality of pieces of magnetism data q<SB POS="POST">1</SB>to q<SB POS="POST">N</SB>sequentially output from the three-dimensional magnetic sensor 60 are distributed in the vicinity of an ellipsoid around an optimal center c<SB POS="POST">EOP</SB>, an optimal ellipsoid correcting matrix T<SB POS="POST">OP</SB>for converting coordinates on the ellipsoid into coordinates on a sphere around the optimal center c<SB POS="POST">EOP</SB>, by minimizing an ellipsoid optimizing function f<SB POS="POST">EL</SB>(T, c) of which variables are elements of a variable matrix T being a symmetric matrix, converts the coordinates indicated by the magnetism data q<SB POS="POST">i</SB>into coordinates indicated by converted magnetism data s<SB POS="POST">i</SB>, using the optimal ellipsoid correcting matrix T<SB POS="POST">OP</SB>and a coordinate indicated by the optimal center c<SB POS="POST">EOP</SB>, and calculates a direction of geomagnetism Bg on the basis of the coordinates indicated by the converted magnetism data s<SB POS="POST">i</SB>and the coordinate indicated by the optimal center c<SB POS="POST">EOP</SB>. <P>COPYRIGHT: (C)2013,JPO&INPIT |
