Experimental Study On The Effect Of Adjustable Parameters On Two-way Satellite Time And Frequency Transfer

Based on the basic theory of two-way satellite time and frequency transfer (TWSTFT),two parts work are finished in this paper. Part one is the work of data pre-processing.Quasi-Accurate Detection of Gross Errors（QUAD）is applied to pre-process the dataof TWSTFT experiments for the first time. In part two, experiments are analysed. Inorder to study the effect of adjustable parameters on TWSTFT, zero baselineexperiments and three stations closure experiments are analysed and researched.With the development of science and technology, people’s requirement on theprecisionof measurement becomes higher and higher. And it’s getting more and moreimportant to seek an effective strategy to cope with gross errors. There are some grosserrors caused by various factors in two-way satellite time and frequency transferexperiments. The existence of these gross errors will bring non-ideal result toadjustment and will decrease the precision of the clock error comparison between twostations. Therefore, it’s necessary to detect gross errors and reject or correct them.QUAD is applied to pre-process the data of TWSTFT experiments for the first timein this paper, which is different from the methods of residual test in the past. QUAD isproposed by OU Jikun and is a new idea and a distinctive method that can be used fordetecting gross errors. The gross errors can be located exactly and the estimators ofthe gross errors can be got by this method. In the part of data pre-processing, themathematical model on real errors of observations is established in this paper.However, the model is rank-deficient. In order to resolve this problem effectively, thepaper introduces the algorithm of combining parameters, and applies QUAD to datapre-processing. The method programs opportune algorithms and resolves the problemof detecting gross errors. In the end, the method has been verified to be successful bycalculating simulated data and practical measured data. The accuracy of the resultsbetween QUAD and the old method are in the same order of magnitude. However, thesmaller gross errors in observations can be detected easily by the method of QUAD,which applies a new method of data pre-processing to TWSTFT experiments.In order to study the effect of spreading code rate and RF frequency on TWSTFT,the TWSTFT system of Chinese Academy of Sciences is used. Zero baselineexperiments and three stations closure experiments are researched. From the result ofzero baseline experiments we can see that with the increase of spreading code rate, the stability of TWSTFT becomes better and better. Compared to the experiment result of6366MHz, the stability of TWSTFT is a little better when the RF frequency isswitched to6047MHz.From the result of three stations closure experiments we know that with theincrease of spreading code rate, Root-Mean-Square(RMS) of TWSTFT gets smallerand smaller. The stability of TWSTFT gets better when the spreading code rateincreases. Different spreading code rates also have influence on the systematic errorsof TWSTFT. The switching of the two RF frequency has no influence on the stabilityof TWSTFT basically. However, different RF frequency have influence on thesystematic errors of TWSTFT.