异源信标对同波束VLBI差分时延实时解算的影响

发布时间：2018-04-19 01:29

本文选题：同波束VLBI + 信标源　；参考：《天文学进展》2014年01期

【摘要】：日本SELENE的两个小卫星Rstar和Vstar都搭载两个晶振作为VLBI多频点信标源的基准,其中一个晶振产生信号f1,另一个晶振产生信号f2和f3。通过分析Rstar和Vstar的同波束VLBI观测数据,发现利用来自异源的两对频点信号(f1,f3)的相关相位解算差分时延时,由差分频率与仪器时延差相乘所引起的相位误差较大,从而导致差分群时延的精度不高以及差分相时延的实时解算成功率不高。利用来自同源的两对频点信号(f2,f3)的相关相位来求解差分时延,与利用异源信标相比,上述误差值为原来的1/64,使得差分群时延精度提高,差分相时延实时解算成功率也大幅提高。分析结果表明,若把台站间的仪器时延差(包括钟差)修正至1μs时,将有望进一步提高差分相时延的解算成功率。基于上述分析结果给出了适宜于同波束VLBI观测的同源信标源设计方案。
[Abstract]:Two small Japanese SELENE satellites, Rstar and Vstar, both carry two crystal oscillations as the reference for VLBI multi-frequency beacon sources, one of which generates signals f1 and the other produces signals f2 and f3.By analyzing the same beam VLBI observation data of Rstar and Vstar, it is found that the phase error caused by multiplying the difference frequency with the instrument delay is larger when the relative phase of the two pairs of frequency signals from different sources is used to solve the differential delay.Therefore, the precision of differential group delay is not high and the success rate of real time solution of differential phase delay is not high.The correlation phase of two pairs of frequency signals from the same source is used to solve the differential delay. Compared with the heterogenous beacon, the above error is 1 / 64 of the original, which improves the accuracy of the differential group delay and improves the success rate of the real time solution of the differential phase delay.The results show that if the instrument delay difference (including clock difference) between stations is corrected to 1 渭 s, the success rate of calculating differential phase delay will be further improved.Based on the above analysis results, a design scheme of homologous beacon source suitable for the same beam VLBI observation is presented.
【作者单位】：中国科学院上海天文台;
【基金】：中国科学院百人计划国家自然科学基金(11273049,11073048) 863项目(2012AA121603) 空间毫米波VLBI阵列背景型号(XDA04060705) 上海市科学委员会(08DZ1160100)
【分类号】：P12

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