微型激光测距与甚长基线干涉测量的天线旋转中心的直接解法

精确确定SLR (Satellite Laser Rainging)和VLBI (Very Long Baseline Interferometry) 天线的旋转中心是并址站归心基线测量的关键问题。本文利用两类约束条件建立旋转中心与观测标志之间的直接关系，第1类约束是SLR或VLBI上的观测标志绕其旋转轴旋转形成1个由平面和球面相割得到的平面圆，第2类约束是SLR或VLBI的旋转中心与其垂直轴旋转圆心在同一铅垂线上，与其水平轴旋转圆心在同一水平面上。根据这两类约束条件建立相应的条件方程，利用标志点观测值直接解算旋转中心的坐标及其协方差阵。利用我国2个GNSS (Global Navigation Satellite System) 与SLR或VLBI并址站的实测数据，求解了基于本文直接解法的空间归心基线。结果表明，与已有分步解的差值优于1mm。

Direct solution of SLR and VLBI antenna rotation center

To accurately determine the rotation center of SLR (Satellite Laser Ranging) and VLBI (Very Long Baseline Interferometry) is a key problem in surveying co-located tie vector. This paper develops an approach of directly solving the collocated tie vector by using two kinds of constraints between SLR and VLBI’s antenna rotation center and observation marks. The first constraint is that the mark forms a planar circle when it rotates along with its rotation axis, which can be modeled as the intersection of a plane and a sphere. The second constraint is that the rotation center lies in the same plumb line with the rotation center of vertical axis, and in the same plane with the rotation center of horizontal axis. The corresponding condition equations are established according to the two kinds of constraints. The tie vector and its covariance matrix are directly resolved by using the observations of the mark points. The space differences baseline are solved based on the direct approach using measured data of seven GNSS (Global Navigation Satellite System) and SLR or VLBI co-location. The results show that the difference is better than 1mm compared with two step solutions.