Very-Long-Baseline Interferometry (VLBI) Astrometry

采用甚长基线干涉测量技术 环绕着地球仪的射电望远镜对致密的射电进行成像 角分辨率达到100微弧秒的源 并精确地确定它们的相对位置 接近10微弧秒 这笔赠款将由哈佛大学的夏皮罗博士用于 继续使用VLBI技术（a）确定银河系和 河外距离和哈勃常数Ho，（B）的估算 为了测量和设置无线电源的自行的界限， 以及（c）改进河外射电源参考 frame.

The technique of very long baseline interferometry (VLBI) is used with radio telescopes girdling the globe to image compact radio sources with an angular resolution reaching 100 microarcseconds and to determine their relative positions with an accuracy approaching 10 microarcseconds. This grant will be used by Dr. Shapiro at Harvard University to continue using the VLBI technique (a) to determine galactic and extragalactic distances and to estiamte Hubble's constant Ho, (b) to measure and place bounds on proper motions of radio sources, and (c) to improve the extragalactic radio source reference frame.