工程测量平面控制网计算基准面选定方法

Selection Method of Calculating Datum Surface of Engineering Surveying Horizontal Control Network

通过分析距离和水平方向两类典型观测值因计算基准面选择不同而导致的精度损失,设计了一种便捷、实用的工程控制网计算基准面选定方法。以平面、球面、旋转椭球面和三轴椭球面为选择对象,研究了基准面的选择对距离和角度观测值归算精度的影响规律。以数学表达形式简单、精度满足需求为选取原则,以测区范围和精度要求为约束条件,根据归算精度差异随测区范围的变化规律,给出了基准面选取参考图。该参考图可为平面控制网计算基准面的选择提供便捷的指导。

By analyzing the accuracy loss of typical observations,such as distance and horizontal direction,which is caused by the selection of calculating datum surface,a convenient and practical method was designed for selecting the calculating datum surface of engineering control network.By taking plane,spherical surface,rotational ellipsoid surface and triaxial ellipsoid surface as selections,the influence rule of calculating datum surface on the reduction accuracy of typical observations was studied.Based on the selection principle that the accuracy satisfied requirement and its mathematical expression of the surface need to be as much simple as possible,taking measurement area and accuracy requirement as constraint conditions,the reference diagram for datum selection was obtained according to the variation rule of the difference of reduction accuracy with the range of the survey area,which will provide a convenient guidance for the selection of calculation datum of horizontal control network.