| 摘要 |
PROBLEM TO BE SOLVED: To calculate the direction of geomagnetism correctly while limiting a process load on a terminal device.SOLUTION: A server apparatus SV, for use in communication with each of plural terminal devices 1 each including a three-dimensional magnetic sensor 60 and a component 2 that includes a soft magnetic material 21, includes: an ellipsoid correction unit 200 for calculating, when N-piece of magnetic data qthrough qare supplied from a given terminal device 1, a coordinate of an optimal center point cbeing the center point of an optimal ellipsoid Vthat is defined so as to have in the vicinity thereof a coordinate indicated by each of the N-piece of magnetic data qthrough qand calculating an optimal ellipsoid correction matrix Tfor use in coordinate-conversion from a coordinate on the optimal ellipsoid Vinto a coordinate on a spherical surface Shaving the center at the optimal center point c; a data control unit 710 for generating response information RES on the basis of the coordinate of the optimal center point cand the optimal ellipsoid correction matrix T; and a server-side transmission/reception unit 720 for transmitting the response information RES to the given terminal device 1. |
