EARTH STATION AND FREQUENCY CORRECTION METHOD

PROBLEM TO BE SOLVED: To provide an earth station and a frequency correction method, capable of securing frequency stability within a criterion range when performing low-speed transmission in an RF frequency band, using a crystal oscillator having lower stability than a highly stable crystal oscillator.SOLUTION: The earth station includes a calculation unit and a correction unit. The calculation unit calculates a frequency deviation, which becomes the operation standard of the self-device, on the basis of a plurality of signals received through a satellite. The correction unit corrects a clock frequency which is output from an oscillator having frequency stability lower than a predetermined threshold, on the basis of the calculated frequency deviation.SELECTED DRAWING: Figure 2 【課題】低速伝送をＲＦ周波数帯で行う場合に高安定な水晶発振器よりも安定度の低い水晶発振器を用いて基準範囲内の周波数安定度を確保することができる地球局及び周波数補正方法を提供することである。【解決手段】実施形態の地球局は、算出部と、補正部とを持つ。算出部は、衛星を介して受信された複数の信号に基づいて、自装置の動作基準となる周波数の偏差を算出する。補正部は、算出された前記周波数の偏差に基づいて、周波数安定度が所定の閾値未満の発振器から出力されるクロックの周波数を補正する。【選択図】図２