Update manner of the search range, receiving the satellite signal from control supervisor

摘要

PROBLEM TO BE SOLVED: To provide a method, etc. of updating a search range capable of shortening a duration time of a state of a reception frequency deviating from the search range due to drift variation during position measurement, while limiting expansion of the search range by using the drift calculated by using a reference frequency.;SOLUTION: This method comprises steps for: continuously calculating a first drift df1 of a local oscillator 34a using a reference frequency; calculating a search range of a satellite signal using the first drift df1; calculating a second drift df2 of the local oscillator 34a using a reception frequency of the satellite signal; updating the search range using the second drift df2; and updating the search range using the first drift df1 during the calculation of the second drift df2 even when an error α1 of the first drift is larger than an error α2 of the second drift.;COPYRIGHT: (C)2008,JPO&INPIT