摘要 |
When position measurement accuracy of the present position which the base station distance and position measurement part measures from radio waves coming from base stations is not good, a GPS distance and position measurement part measures the present position from radio waves coming from GPS satellites. When position measurement accuracy of the present position obtained by the GPS distance and position measurement part is not good, a position measurement accuracy analysis part compounds the present position obtained by the base station distance and position measurement part with the present position obtained by the GPS distance and position measurement part, and calculates a new position within a range of overlap between a position measurement error of the present position obtained by the base station distance and position measurement part and a position measurement error of the present position obtained by the GPS distance and position measurement part. |