High Precision Relative Astrometry by Means of '4-Element' VLBI Observations

通过“四元素”VLBI 观测进行高精度相对天体测量

• 批准号: 03452015
• 负责人: SASAO Tetsuo
• 金额: $ 0.77万
• 依托单位: National Astronomical Observatory
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1991
• 资助国家: 日本
• 起止时间: 1991 至 1992
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452015/
• 关键词: 4-element VLBI; multi-view differential VLBI; fringe phase difference; tropospheric phase fluctuations; phase fluctuations in signal transmission system.; 伝送系内位相変動; 大気ゆらぎ; KNIFE; 位相追尾

This research aims at measuring with high accuracy the relative positions of closely spaced radio sources by making use of simultaneous multi-view differential VLBI observations of those sources with '4-element' VLBI system. Since destructive effects of phase fluctuations occurring in the atmosphere and frequency standards must be largely compensated in this method of observations, one can expect to obtain very precise VLBI fringephase difference as an observable. For the purpose, we used 45-m mm-wave telescope and 6-m VLBI antenna at Nobeyama Radio Observatory/NAO, as well as 34-m and 26-m antennas at Kahshima Space Research Center of Communications Research Laboratory, forming dual baselines with length of about 200 km. After three preparatory experiments held in March and May of 1992, we successfully conducted the main 24-hour observations on June 27 - 28, 1992.10 pairs of radio sources with angular separation ranging from 0.074 to 10.35 degrees, as well as a gravitational lens cand … More idate PKS1830-211, were observed. Each pair was observed with two baselines alternately or by switching to a strong calibration source for the purpose to compensate the effects of the phase delay within the signal transmission systems. Cross-correlation processing carried out with K-3 correlator at Kashima revealed good fringes for almost all sources, thus showing the basic feasibility of the 4-element VLBI observations and yielding a number of multi-view differential VLBI data for the first time. The data were format-converted and now are analyzed on the main frame computer of NAO, Mizusawa.Along with the experiments, we successfully developed a statistical model of the atmospheric fluctuation effects upon the multi-view differential VLBI observations, and showed that the high accuracy is really achievable as far as the atmosphere is the primary limiting factor for the precise observations. We developed also an promising algorithm of long-time integration for relatively weak radio sources and models for phasedelays due to the distortion of the transmission cables. These results will be used in interpreting the analyzed data. Less

本研究旨在利用“四元”VLBI系统对密集射电源的多视角同时差分VLBI观测，高精度地测量密集射电源的相对位置。由于这种观测方法必须在很大程度上补偿大气和频率标准中出现的相位起伏的破坏性影响，因此可以期望获得非常精确的VLBI条纹相位差作为观测量。为此，我们使用了Nobeyama射电天文台/NAO的45米毫米波望远镜和6米VLBI天线，以及通信研究实验室鹿岛空间研究中心的34米和26米天线，形成了约200公里长的双基线。在1992年3月和5月进行了三次预备性实验后，我们于1992年6月27 - 28日成功地进行了24小时的主要观测。10对射电源的角距为0.074 - 10.35度，以及一个引力透镜， ...更多信息 idate PKS1830-211。每一对都是用两个基线交替观察的，或者通过切换到一个强校准源来观察的，目的是补偿信号传输系统内相位延迟的影响。在鹿岛用K-3相关器进行的互相关处理显示了几乎所有源的良好条纹，从而表明了四元VLBI观测的基本可行性，并首次获得了一批多视差分VLBI数据。沿着实验，我们成功地建立了大气起伏对多视差分VLBI观测影响的统计模型，并表明只要大气是精密观测的主要限制因素，高精度是可以实现的。我们还开发了一个有前途的算法，长时间的积分相对较弱的无线电源和模型的相位延迟，由于传输电缆的失真。这些结果将用于解释分析数据。少

项目成果

Tetsuo SASANO: "High Precision Geodesy and Astrometry with Antennacluster-Antennacluster VLBI System" Proceedings of the International Workshop for Reference Frame Establishment and Technical Development in Space Geodesy (IRIS,Janusry 18-21,1993,Tokyo). (

Tetsuo SASANO：“利用天线簇-天线簇 VLBI 系统进行高精度大地测量和天体测量”空间大地测量参考系建立和技术开发国际研讨会论文集（IRIS，1993 年 1 月 18-21 日，东京）。

花田 英夫: "月面電波源の相対VLBI観測計画" VLBI国内ネットワークシンポウジウム. 106-109 (1992)

花田秀雄：《月球射电源相对VLBI观测计划》VLBI国内网络研讨会106-109（1992）。

笹尾 哲夫: "KNIFE 4素子法VLBI実験" KNIFE シンポジウム集録. 94-98 (1991)

Tetsuo Sasao：“KNIFE 四元素 VLBI 实验”KNIFE 研讨会论文集 94-98（1991）。

久慈 清助,川口 則幸: "VLBIバックエンドKー4国際共同観測方式調査" 国立天文台・水沢観測センタ-技報. 3. 120-140 (1991)

Kiyosuke Kuji、Noriyuki Kawaguchi：“VLBI 后端 K-4 国际联合观测方法调查”日本国家天文台/水泽观测中心 - 技术报告 3. 120-140 (1991)。

Katsuhisa Sato,Tadayoshi Hara,Mitsumi Fujishita,Seisuke Kuji,Seiitsu Tsuruta,Yoshiaki Tamura,etc.: "A pplication of Phase Stabilized Optical Fiber in Transmission of Reference and IF Signals in VLBI Observation" IEEE Transactions on Instrumentation and Me

Katsuhisa Sato、Tadayoshi Hara、Mitsumi Fujishita、Seisuke Kuji、Seiitsu Tsuruta、Yoshiaki Tamura 等：“相位稳定光纤在 VLBI 观测中参考信号和中频信号传输中的应用” IEEE Transactions on Instrumentation and Me