卫星双向法与卫星测距

Two Way Satellite Time Transfer（TWSTT） and Satellite Ranging

卫星双向时间比对是目前远距离台站时间比对精度最高的时间同步技术,时间比对精度达几百皮秒,比GPS共视技术的时间比对精度几乎高一个数量级。中科院国家授时中心根据多台站卫星时间比对经验,提出利用卫星双向比对技术进行卫星测距（称转发器定轨）。实验证明：利用卫星双向技术（卫星需要转发器）进行卫星测距,可得到高精度卫星轨道（内符精度为几厘米）和卫星预报轨道。

TWSTT （ Two Way Satellite Time Transfer） is a method of the most accurate time transfer at distant stations. The accuracy is up to a few hundred picoseconds （ ps）. Its accuracy by TWSTT is much better than that of GPS common view. Based on the experience of time transfer on multi-stations, a new method of satellite ranging was proposed by Na- tional Time Service Center, the Chinese Academy of Sciences. Using the TWSTI＂ method, the distance between station and satellite is determined accurately. The results for the above method show that satellite orbit can be determined with high accuracy within＇a few centimeters and it is suitable for the prediction of satellite orbit.