Abstract According to Newton's law of universal gravitation, the movement of matter and the change in density cause a gravitational variation. Due to the anisotropic distribution of matter, the vertical and the normal directions at a point on the ground are probably inconsistent, which is referred to as the deflection of the vertical (DOV) and is indispensable to astrogeodetic and geophysics research. Two new non‐optical methods, including small network transformation and azimuth‐axis inclination inversion, are proposed to determine the DOV at a very long baseline interferometry (VLBI) telescope at the Urumqi station. A generalized expression of the pointing calibration model considering axis‐related errors is also presented. Therefore, the pointing calibration model and indirect model used for reference point (RP) determination are unified by redefining their coordinate system, angle direction, and axis‐related errors. The DOV given by the small network transformation agrees well with the DOVs determined by the real surveying and other different models. Due to the possible asymmetric coverage of calibrating sources in the north‐south direction in antenna pointing calibration, the north‐south DOV component based on azimuth‐axis inclination inversion differs from the surveyed value. However, the west‐east DOV component fits well in both direction and magnitude. The proposed methods enable the VLBI telescope to sense the direction of the local plumb line by introducing local leveling. We also establish the connections among VLBI delay observation, RP determination, and telescope pointing calibration, which has a benefit to multi‐tech systematic error identification, monitoring, and correction. The research indicates that telescope point calibration can also be taken as a regular technique to monitor systematic error.

The complete expression of pointing calibration model (PCM) for the axis related errors (ARE) of the radio telescope is derived directly. The definition of the common axis related parameters in both pointing correction model of ARE and Lösler's indirect model (IM) is unified, then the relationship between PCM and IM of the radio telescope is established. Thus, the deflection of the vertical (DOV) determination of VLBI stations is realized by using radio telescope azimuth axis information. As a direct surveying approach, this method does not rely on special DOV surveying equipment. It could only depend on pointing calibration surveying data for telescope aperiodic maintenance and the local surveying data including leveling. Verified by a variety of DOV surveying methods, the DOV obtained by our method shows a good agreement with real surveyed DOV in west-east component. Owing to the non-uniform distribution of the radio sources sky coverage of the station during its pointing calibration, the north-south component of DOV has the same direction as the surveyed DOV, but has a difference in value. In the future, further providing an optimized telescope pointing calibration, the high precision surveying of DOV will be obtained by using VLBI telescope azimuth axis.

推导了传统全球卫星导航定位系统(GNSS)测定垂线偏差(Deflection of theVertical,DOV)形式误差的表达式;提出一种可用以解算并置站DOV的小网参数转换法.利用乌鲁木齐南山多技术并置站控制网观测信息,开展了算法验证,并对该站内多个地点DOV开展了实测.结果表明,高精度的小网DOV仅由点位观测精度最高、覆盖面积最广的3个站点决定.个别精度较差的点会为DOV的测定值带来较大的不确定性;采用小网转换法所解算的DOV与实测值间的一致性分别为?2.3′′±4.3′′(子午分量)和0.2′′±4.6′′(卯酉分量);小网转换求取DOV的方法在精度上与经典的GNSS水准方法相当,但步骤更加简便.鉴于多技术并置站会不定期地开展本地测量,可利用该方法实现多技术并置站DOV的零成本长期监测.

为在本地测量中更精确地测定VLBI(very long baseline interferometry)天线参考点(reference point,RP)点位,分析了水平钢轨残余形变对四轮座架式天线的影响,首次提出并推导了用以改正归心解算靶标点(target point,TP)坐标的水平钢轨残余形变模型,结合实测靶标坐标与钢轨水准数据,解释了TP坐标残差中的系统性效应,精化了TP理论坐标,显著提高了参考点测定精度.结果 表明,采用水平钢轨残余形变改正模型与估算模型可分别使靶标坐标归心拟后残差中误差提高50％和65％,归心精度均可提高约30％.此外,本钢轨残余形变估算模型还可有效用于该类天线钢轨形变的监测.

介绍了2011年中国科学院新疆天文台南山站GPS和25 m VLBI天线的归心测量方案、局域三角测量网、高程控制网与靶标交会测量方法及资料解算.利用测量数据,首次建立了南山GPS与VLBI空间大地测量技术并置站本地连接参数,测量精度优于1 mm.

新疆天文台南山GPS观测站是国内、国际建立和维持ITRF进行全球动力学研究的参考点之一，由于其测站的特殊地理位置，测站的GPS观测受到国际及国内相关学者的重视。为了确保测站GPS观测数据的精度，对观测数据进行质量评定。选取2012-11-15~12-15 GUAO站GPS观测数据进行统计分析，重点分析了信噪比的强弱及多路径效应对观测数据的影响。

随着城市管理科学化的要求，建设一个信息化、数字化的乌鲁木齐首府成为迫切的需要。为了满足城市建设的需要，本文阐述了乌鲁木齐建立GNSS CORS站的建设目标及系统的构成，重点对GNSS CORS参考站网子系统的选址、基墩建站要求、仪器指标、精度及环境效果等进行了分析研究，并对省级GNSS基准网的应用需求和发展前景进行了阐述。

新疆天文台同时拥有 GPS 与 VLBI 空间大地测量技术,是国际、国内 VLBI 观测网与 GPS 观测网的重要观测台站之一.本文介绍了2011年中科院新疆天文台南山观测站首次进行 GPS 与 VLBI25米射电望远镜的本地连接测量,文中着重介绍了本地连接的控制网的布设、观测方法以及数据处理方法.

2011年8月在新疆天文台南山观测站首次进行了GPS与VLBI空间大地测量技术并置站的本地连接测量。针对南山并置站,本文在建立、优化南山GPS控制网的基础上,探讨本地连接测量中GPS数据处理的方法、精度。通过对GPS控制网7 d连续观测和基于IGS精密星历的GAMIT基线处理、三维空间平差,结果表明:基线在N、E和长度方向的重复性在0.3~0.4 mm,U方向分量重复性为1.4 mm,基线相对精度为0.8×10-8,达到《全球定位系统(GPS)测量规范》(GB/T 18314—2009)中A级网的精度要求,GPS控制点在ITRF2008系统下的坐标精度均优于0.5 mm。

利用GAMIT软件,采用有基准算法对乌鲁木齐南山观测基地新建GPS跟踪站GUAO的观测资料进行了归算,结果表明该站观测资料的质量是可靠的,并首次获得了该站在ITRF2000中毫米级精度的地心坐标.

乌鲁木齐天文站于2001年按照国家重大科学工程"中国地壳运动观测网络"基准站的要求,在乌鲁木齐南山站建立了GPS跟踪站(GUAO:GPS station of the Urumqi Astronomical Observatory),现已加入IGS网,并向IGS发送GPS观测资料.利用GAMIT软件,采用有基准算法对新建GPS跟踪站的观测资料进行了归算和精度分析,首次获得了该站在ITRF2000中毫米级精度的地心坐标.

In this paper,briefly introduces the consist and development of GPS and how to monitor the precipitable water vaper based on the data of GPS sites. It also proved high accuracy, nearly continuous real time sequence of precipitable water vaper, and rain forecast and weather forecast.