It is an important mission of Geodesy to improve an accuracy of control networks and to establish the geocentric coordinate system via combined satellite and terrestrial network adjustment.

通过地面网与卫星网的联合平差，以改善网的精度和建立高精度的地心坐标系统，是当前大地测量的一项重要任务。

youdao

Based on the practice of high-grade highway tunnel GPS survey, establishment and data processing method for independent coordinate system of tunnel GPS control network are introduced in the paper.

本文根据生产实践，介绍了高等级公路隧道GPS控制网的建立及用于施工坐标系的数据处理方法。

youdao