GPS RECEIVER

摘要

PROBLEM TO BE SOLVED: To prevent deterioration of accuracy of time prediction in a GPS receiver. SOLUTION: A positioning part 103 executes a positioning operation. A counter part 104 counts a time even during suspension of the GPS receiver. An error measuring part 105 measures an error of the counter part 104 by using an accurate time by the positioning operation. Time data and error data are preserved a measurement result preservation part 106. An error correction part 107 corrects a value of the counter part 104 by using the error data. A time prediction accuracy evaluation part 108 calculates the degree of deterioration of positioning accuracy when the correction is executed by using the error data. A time prediction part 109 calculates the time by using correction data. A time setting part 1l0 sets information for deciding a transmission time by the result of the time prediction part 109, but if the deterioration of the positioning accuracy is large setting is suspended following instruction by the time prediction accuracy evaluation part 108.