根据卫星双向共视法时间比对的基本原理,详细推导该时间同步方法在地心惯性系中精确到卫星和地面站速度的二次幂以及加速度的一次幂的计算模型,并以GEO卫星和GPS卫星为例,分析该计算模型中的距离改正项时延对地面站间相对钟差的影响量级。结果表明:对于GEO卫星、GPS卫星与地面站之间的比对,当要求1ns的计算精度时,距离改正项时延只需要考虑到卫星速度项、地面站速度项的影响;当要求1ps的计算精度时,还需要考虑到卫星速度二次幂项、卫星加速度项、地面站与卫星相对钟差对卫星速度项、地面站间相对钟差对地面站速度项的影响。
Time synchronization is one of the pivotal technologies in the design of satellite navigation and positioning system.According to the principle of time comparison by two-way satellite common-view,its computational model in the earth-centered inertial reference frame with the second order of the velocity and the first order of acceleration of satellite and ground-station is particularly deduced.Taking the GEO and GPS satellites as examples,the magnitudes of the influences of every item in the distance correction time delay of the computational model to the relative clock difference between ground stations are analyzed. And the results show that when having time comparison between the GEO or GPS sat- ellite and the ground station, the velocity of satellite and ground station should be taken into account in lns computational precision~ and the second order of the satellite velocity, the satellite acceleration, the effect of relative clock difference between ground station and satellite on the satellite velocity, the effect of relative clock difference between ground stations on the ground station velocity should also be taken into account in lps computational precision.