空间VLBI阵列观测设计和编制软件的研究和开发

VLBI (Very Long Baseline Interferometry) is the technology providing the highest angular resolution in mordern astronomical observations. The Chinese Academy of Sciences carries out the Pre-research Space Science proejct named “Painting Astronomical Object''s Portrait”, one of the missioin is to launch two mm-wavelength radio telescopes onboard the satellites which consist of Space VLBI together with the ground-based VLBI telescopes. The highest angular resolution of the proposed Space VLBI is 20 micro-arcsecond, enabling to image the Supermassive Black Holes and 他to explore the emission zone in the immediate vincinity of the black holes...During the pre-research phase, an urgent task is to perform the simulations of the satellite orbites in order to acquire good uv coverage of the Space VLBI. Based on the simulations, the orbital parameters and array configuration are optimized. During the on-orbit phase, software packages with functions of designing and scheduling observations are required to support the astronomers. In addition, special considerations should be made to improve the accuracy of the delay and rate models employed in the VLBI correlator. ..The current proposal will study the Space VLBI configuration, satellite orbit simulation, dynamically scheduling the observations of the space telescope, on the basis of the satellite orbit simulation software package SPAS used for VSOP. We aim to develop a specific software package for the Chinese mm-wavelength Space VLBI project and it also matches the requirements of the future Space sub-millimeter VLBI array.

在当前天文观测中，VLBI是拥有最高空间角分辨率的技术。中国科学院实施的空间科学预先研究项目“天体肖像“计划之一是发射两颗卫星搭载空间毫米波VLBI望远镜，与地面射电望远镜组成“空-地”干涉阵，最高分辨率达到20微角秒，能够对超大质量黑洞等致密天体成像，探测黑洞周围的吸积盘和喷流等辐射结构。. 在深化论证阶段，为了获得良好的空间VLBI阵uv覆盖，需要采用数值模拟仿真空间VLBI的轨道，从中选择最优的轨道参数和阵形组合；在空间VLBI阵列任务阶段，需要向科学家提供观测设计和计划工具；为了满足空间VLBI观测相关处理需求，需要提供高精度的理论模型。. 为此，本项目将在VSOP仿真软件SPAS基础上, 对空间VLBI阵列观测仿真、观测编制和高精度理论模型计算进行研究，开发空间VLBI阵观测设计和编制的软件系统,满足中国空间VLBI阵列和未来亚毫米波空间望远镜阵组阵列的需求。

在当前天文观测中，甚长基线干涉测量（Very Long Baseline Interferometry，VLBI）是拥有最高空间角分辨率的技术。为了追求更高分辨率和探测与超大质量黑洞相关的致密天体，中国科学院的空间科学预先研究项目之一计划发射两颗空间VLBI卫星，与地面射电望远镜组成“空-地”干涉阵。. 为了获得最优空间VLBI阵的设计，需要研发空间VLBI阵观测仿真功能；在空间VLBI阵列任务阶段，需要向科学家提供观测设计和计划工具；为了满足空间VLBI观测相关处理需求，需要提供高精度的理论模型。. 本项目开发实现了一个高精度VLBI理论时延软件，可以计算射电源和探测器的理论时延。对于河外射电源，理论时延差为ps量级；对于探测器，理论时延精度为ns量级。使用软件我们还能够计算空间VLBI观测的UV覆盖，便于空间VLBI阵观测设计，能够满足中国空间VLBI阵列的的需求。