Initial result of the Chinese Deep Space Stations’ coordinates from Chinese domestic VLBI experiments

Abstract

China’s Lunar Exploration Program (CLEP) prompted the design and construction of the globally distributed Chinese Deep Space Network (CDSN). This network consists of Jiamusi and Kashi stations in China, and Zapala station in Argentina. However, the positions of Jiamusi and Kashi are not accurate enough for future Chinese deep space missions, and geodetic Very Long Baseline Interferometry (VLBI) is the most effective way to determine their positions. Since the CDSN stations are equipped with narrow-band receivers, they cannot participate in current international VLBI sessions in which wide-band frequencies are utilized. Thus a cooperative geodetic program of the CDSN and Chinese VLBI Network (CVN, the VLBI tracking subsystem of the CLEP) was initiated to determine their positions, in which specially designed frequencies can be utilized, and some CVN stations can act as position reference stations owing to their precise positions from long-term international VLBI observations. Primary results have been obtained from the CDSN–CVN combined domestic VLBI experiments from September 28, 2014, through December 10, 2015. The positions of Jiamusi and Kashi are determined to be better than 10-mm precision in the X, Y, and Z directions, which are improved by a factor of approximately 20 over their a priori values.

摘要

在探月工程的带动下, 我国设计并建设了全球布局的中国深空网, 包括国内的佳木斯和喀什深空站, 以及位于阿根廷的萨帕拉深空站。 然而, 佳木斯和喀什深空站的站址精度无法满足我国未来深空探测任务的需求, 而测地 VLBI (甚长基线干涉测量) 方法是最有效的站址标定方法。 由于中国深空站配置的是窄带接收机, 无法参加目前国际 VLBI 的宽带观测, 因此只能寻求与中国 VLBI 网 (我国探月工程的测轨分系统) 开展联合观测实现站址标定, 这样可以协商采用专门的观测频率, 且中国 VLBI 网的部分台站经过长期参加国际 VLBI 联测, 已经具备极高精度的站址, 可以作为站址标定的参考站。 通过处理 2014 年 9 月 28 日至 2015 年 12 月 10 日开展的中国深空网—中国 VLBI 网联合观测的数据, 我们解算得到了佳木斯和喀什深空站的站址, 二者的 X、 Y、 Z 分量的精度均优于 10mm, 相对于站址初标精度提高了大约 20 倍。

创新点

• 1、 采用兼容频率设置开展窄带—宽带 VLBI 联合观测, 既保证了数据的兼容性, 又充分发挥了宽带的优势

• 2、 利用速度场插值法获取了佳木斯、 喀什深空站的先验速度, 并约束其全局参数解

• 3、 首次得到了佳木斯和喀什深空站优于 10mm 形式精度的站址, 相对于站址初标精度提高了大约 20 倍