天文学进展Issue(1)：128-136,9.DOI:10.3969/j.issn.1000-8349.2014.01.08
异源信标对同波束VLBI 差分时延实时解算的影响
Influence of Signals from Different Sources on the Real-time Resolution of Differential Time Delay in Same Beam VLBI
摘要
Abstract
Rstar and Vstar are two satellites of Japanese SELENE pro ject, each carries two crystal oscillators on board as the sources of VLBI signals, one generates frequency f1, the other generates frequency f2 and f3. Analysis of the VLBI same-beam data from Rstar and Vstar shows that much phase error was generated by differential frequency multiplies differential instrumental delay, when using the correlation phases of frequency f1 and f3 to resolve differential time delay, thus the accuracy of differential group delay was impaired, and the chances of successfully resolving differential phase delay were low. This paper shows the error mentioned above can be reduced by 64 times, when using the correlation phases of frequency f2 and f3 to resolve differential time delay, this improves the accuracy of differ-ential group delay comparing to the first method, and increases the chances of successfully resolving differential phase delay. In addition, this paper shows if instrumental delay (in-cluding clock offset) between each two VLBI stations are to be corrected to 1 micro-second level by observing quasars, the chances of successfully resolving differential phase delay can be improved further. We also present a design of onboard radio sources, which is suitable for same beam VLBI observations.关键词
同波束VLBI/信标源/钟差/差分群时延/差分相时延Key words
VLBI/crystal oscillator/clock offset/differential group delay/differential phase delay分类
天文与地球科学引用本文复制引用
贺庆宝,刘庆会,吴亚军,陈冠磊,郑鑫..异源信标对同波束VLBI 差分时延实时解算的影响[J].天文学进展,2014,(1):128-136,9.基金项目
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) （11273049,11073048）
