| 摘要 |
PROBLEM TO BE SOLVED: To smoothly perform switchover between long-term prediction orbital data and satellite orbital data acquired from a positioning satellite and further to improve accuracy of a position calculation at the time of the switchover.SOLUTION: First, a value of each parameter of hybrid orbital data is initially set by long-term prediction orbital data at the time of an initial position calculation. Then, a position calculation using the hybrid orbital data is performed while the value of each parameter of the hybrid orbital data is being updated by a value acquired every time a parameter of an ephemeris contained in a received GPS satellite signal (positioning signal) is acquired. When acquisition of the ephemeris is completed, the position calculation using the ephemeris is performed thereafter. |
