| 摘要 |
PURPOSE:To achieve a highly accurate calibration of the standard time signal utilizing the existing circuit by a method wherein time in a satellite is transmitted to a ground station utilizing a telemetry circuit to detect errors from the standard time signal thereof and a corrected time data is transmitted to the satellite. CONSTITUTION:A time data 3 of a time generating section 2 is made a telemetry data with a telemetry encoder 4 and transmitted to a ground station through a down link. At the ground station, the data is demodulated with a telemetry signal demodulation section 7, compared with a standard time signal 10 from a standard time generator section 9 by means of a comparison section 11 and then, an error data 12 is inputted into a calibration time computation circuit 14. A correction data for calibration of time calculated with the circuit 14 taking account of a signal delay time or the like is transmitted to a satellite from a calibrated time transmission section 15 and an error data component is detected with a time error detection section 17 to calibrate the time with a time generator section 2. |
