超高精度的甚长基线干涉相位时延推导法及其在我国的应用前景

文章简要介绍了同波束甚长基线干涉(VLBI)观测法和相位时延推导法,报道了上海-乌鲁木齐基线的误差为0.0005m的差分相位时延的观测结果,介绍了"萤火1号"和"福布斯"探测器的同波束VLBI观测技术及正在研究的相位时延推定新方法,展望了超高精度的VLBI相位时延在中国深空探测中的应用前景.     

Investigation of stronger diurnal ERP signals in summer derived from the VLBI CONT08 campaign

A series of very successful Continuous Very Long Baseline Interferometry Campaigns (CONT) have been carried out at irregular intervals since 1994. One of the goals is to support high-resolution earth rotation studies. The most recent CONT08 campaign was conducted with a network of 11 observatories at an increased recording rate of 512 Mbit per second over a fortnightly time span, from which stronger diurnal variations of the Earth Rotation Parameters (ERP) have been detected. We compared the high-frequency ERP from VLBI and GPS observations during CONT02, CONT05 and CONT08 with the atmospheric angular momentum functions derived from the National Centers for Environmental Prediction/National Center for Atmospheric (NCEP/NCAR) during these periods. We attribute the detected diurnal discrepancies between the theoretical models and the CONT08 observations to atmospheric excitations.     

亚太地区空间地球动力学研究计划(APSG)首期VLBI联测结果

1997年 1 0月中国科学院上海天文台与美国宇航局Goddard空间飞行中心(GSFC)成功组织实施了亚太地区空间地球动力学研究计划 (APSG)首期联测中的VLBI观测 .共 6个VLBI站参加 ,包括中国上海和乌鲁木齐站、美国阿拉斯加Gilcreek站和夏威夷Kokee站、日本鹿岛 (Kashima)站及澳大利亚塔斯玛尼亚的Hobart站 .各站之间的基线长度为 1 90 0～ 1 1 0 0 0km ,基线测量重复率约为 1 0× 1 0 ^-9.利用上述台站以往的VLBI观测 ,并结合全球VLBI观测数据进行了综合解算 ,获得了上述 6个VLBI站的基线变化率及台站的运动速率 .特别是检测到上海台和乌鲁木齐站相对于欧亚板块稳定区域分别存在向东 8mm/a和向北偏东 1 4mm/a的运动 ,这些结果直接验证了印度大陆的向北运动影响到了我国西北和东部地区的地壳运动.     

用于"萤火1号"火星轨道器的开环电测技术

中国首个火星探测器"萤火1号"计划于2011年和俄罗斯的火卫一采样探测器一道发射升空."萤火1号"将探测火星的空间环境,并验证深空导航测控与通信技术.与常规的火星探测任务不同,该探测器的轨道与位置测量主要利用天文甚长基线干涉测量技术、开环跟踪测量技术、差分单程测距测速技术、同波束干涉测量技术以及单程多普勒(Doppler)测速技术.     

相关处理系统中的数据再循环技术及实现

介绍一种数据再循环处理模型，该模块成功地应用在Ａｕｓｔｒａｌｉａ Ｔｅｌｅｓｃｏｐｅ Ｎａｔｉｏｎａｌ Ｆａｃｉｌｉｔｙ（ＡＴＮＦ）的一套甚长线射电干涉测量系统（ＶＬＢＩ）的数据相关处理器中，该模块的功能是提高相关处理器处理窄带信号的频率分辨率。     

Measurements of the VLBI experiments during the first campaign of the Asian-Pacific space geodynamics (APSG) program

During the first campaign of the Asian-Pacific space geodynamics (APSG) program in October 1997, two VLBl experiments were successfully organized and coordinated by the Astrometry and Geodesy VLBl Group of Shanghai Astronomical Observatory, the Chinese Academy of Sciences, cooperated with geodetic VLBl group, GSFC, NASA, USA. Six VLBl stations participated in the experiments, including Seshan and Urumqi station of China, Gilcreek station in Alaska and Kokee station in Hawaii of USA, Kashima station of Japan and Hobart station at Tasmania of Australia. Baseline lengths are from 1 900 to 11 000 km and the mean relative uncertainty of the baseline length measurements is 1.0 x 10^-9. In addition, the rates of the baseline lengths among the six stations and their three-dimensional velocities are solved out via global analysis of the two APSG sessions and the historical observations of the six stations as well as other VLBl observations from the global observation network. These results are appreciable to the studies of the modern crustal movement in the Asian-Pacific region. Especially,an 8 mm/a eastward motion and a 14 mm/a north by northeast motion are detected respectively for Seshan and Urumqi stations relative to the stable part of the Eurasian plate. The motions directly illustrate the effect of the northward movement of Indian plate on the modern crustal motions of the northwestern and the eastern part of China, which is of important significance to the study of the modern crustal motion of China.     

定位归算在嫦娥二号任务实时阶段的应用

该文统计分析了嫦娥二号任务实时阶段的VLBI观测时延和定位结果的精度，讨论了定位归算方法在嫦娥二号卫星关键弧段实时轨迹监测中的应用，从定位归算角度分析了X波段测控体制试验的关联技术指标，为我国后续探月卫星任务进行了有益的方法与软件铺垫，积累了工程与技术实践经验．