| 摘要 |
<p>The satellite signal tracking method performed during the initial phase of satellite tracking operation, wherein three or more GPS satellites in a first orbit are selected for searching in sequence through one receiving channel of a GPS receiver and performing the positioning on the earth upon receipt of navigation data from the captured GPS satellite, whereby, if a first GPS satellite is failed to be caught within a specified period of time, a second GPS satellite among the selected GPS satellites in the same orbit, which is at the furthermost point from the first GPS satellite, is picked out for searching and, further, if any of the selected GPS satellites in the same orbit is failed to be caught, three or more GPS satellites in another orbit are selected for reiterating the same operation as for the first orbit, and these changes of mode provides a quick restart of the position reckoning even when the GPS receiver has lost all the navigation data in a backup memory required therefor and an expeditious operation in catching satellite signals for initializing the GPS receiver.</p> |
