| 摘要 |
PROBLEM TO BE SOLVED: To enable determining whether a navigation message from an artificial satellite is normal while restraining a communication processing load on an authentication center used for authenticating whether the navigation message from the artificial satellite used in a satellite positioning system is normal.SOLUTION: It is determined that a navigation message is normal if it has been determined that transmission clock time in accordance with transmission clock time included in a navigation message of which authentication is successful in communication with an authentication center 120 is included in a navigation message received by a satellite receiver 230 from a GPS satellite 2 different from the transmission source of the navigation message of which authentication is successful in communication with the authentication center 120. |
