GPS授时校频方法研究与试验结果

为了解决多目标综合测量系统各测站之间时间同步和频率校准问题,提出了利用GPS(Global Positioning System)单星或多星共视方法进行站间时间同步与校频,给出了这两种方法的计算公式,分析了星历误差、星钟误差、电离层折射误差、对流层折射误差、多径效应和接收机硬件延迟对时间同步精度的影响.为了验证GPS授时校频精度,进行了相关试验.通过与铯原子钟比对,表明利用GPS可实现纳秒级时间同步,校频精度也优于5.0×10-11,多星共视具有更高的同步校频精度. 

Study on GPS timing and frequency calibration method and the test results

To solve the problem of time synchronization and frequency calibration among different stations in an integrated multi-target tracking system, two methods using global positioning system(GPS) through observing one or more GPS satellites in common view are put forward. Calculation formulas are derived, the impacts on time synchronization of error sources such as ephemeris error, satellite clock error, ionospheric error, tropospheric error, multi-path effects and receiver’s hardware delay are analyzed. To validate time synchronization and frequency calibration precision, some related tests were got. Comparing with Cesium clock, it shows that nanosecond level time synchronization can be obtained and the precision of frequency calibration is better than 5.0×10^-11 using GPS. More precise time synchronization and frequency calibration can be achieved by using multi-satellites in common view than using single satellite.