天文固定的三维平差法及应用

ASTRONOMICALCONTROLLED 3D ADJUSTMENT METHOD AND USE

本文研究了制约三维平差发展的两个主要因素：（１）天文观测工作量大，（２）受垂直折光的影响天顶距观测精度低。在此基础上，提出了把天文经纬度作固定的天文固定三维平差法。该方法采用现有的垂线偏差分量来代替外业天文经纬度观测值，并在函数模型中适当处理天顶距垂直折光的影响，获得了满意的结果。另外，本文还针对三维平差观测值种类多的特点，通过试验，认为采用Ｆｒｓｔｎｅｒ近似公式为好。同时，本文给出了边长和天顶距的垂直归心公式。

This paper studies two main factors: a large amount of astronomical measurements and low accuracy of zenith distances effected by vertical refraction, which limits 3D adjustment widely applied to practice. Based on the study, the paper presumes a new astronomical longitudelatitudecontrolled 3D adjustment method that makes use of the deflection components for lack of astronomical logitude-latitude measurements. Through dealzenith distances suitably in the 3D adjustment model we have satisfactory result.