GPS RECEIVER

摘要

PROBLEM TO BE SOLVED: To make more expensive but less stable parts usable for an internal frequency transmitting source by receiving a sent reference frequency and correcting the error of the frequency transmitting source by using the reference frequency. SOLUTION: Data transmitted form each satellite contain accurate orbital data so that a section F can calculate the positions of the satellites. A navigation analyzing section C calculates the location of a user by using timing information from a tracking section B and positional information from the section F and outputs the location and the calculated error of a crystal oscillator 1 is stored in a section H. Since four or more satellites are tracked, the time of the user can be calculated from satellite signals. Reference information received by means of a receiver G is used so as to facilitate the capture of a timing signal from a first satellite which is caught at the starting time. Even when an inexpensive crystal oscillator, a frequency comparator 6 corrects the drift of the oscillator by using frequency information.