Geomagnetism measuring device, method of terrestrial magnetism measurement, and geomagnetic measurement program

摘要

PROBLEM TO BE SOLVED: To accurately calculate a direction of geomagnetism on the occurrence of soft-iron effect.;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 q₁ to q_N sequentially output from the three-dimensional magnetic sensor 60 are distributed in the vicinity of an ellipsoid around an optimal center c_EOP, an optimal ellipsoid correcting matrix T_OP for converting coordinates on the ellipsoid into coordinates on a sphere around the optimal center c_EOP, by minimizing an ellipsoid optimizing function f_EL(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_i into coordinates indicated by converted magnetism data s_i, using the optimal ellipsoid correcting matrix T_OP and a coordinate indicated by the optimal center c_EOP, and calculates a direction of geomagnetism Bg on the basis of the coordinates indicated by the converted magnetism data s_i and the coordinate indicated by the optimal center c_EOP.;COPYRIGHT: (C)2013,JPO&INPIT