关于改善和更新国家大地测量基准的思考

大地测量基准是地理信息系统和测图的基础框架，其建立，维护，改善和更新是国家测绘行政主管部门的重要职责。大地测量基准中的重力基准和坐本身由于自然和人为原因，破损严重，因此顺应科技进步，国家建设和社会发展的需要。

Thoughts on the Improvement and Upgrade of National Geodetic Datum

Geodetic datum is the fundamental frame of geographical information system, surveying and mapping. The establishment, maintain, improvement and upgrade of National Geodetic Datum is one of the main tasks of State Bureau of Surveying and Mapping. It is not only due to the out-of-date of geodetic infrastructure, but also the needs of the development and progress of national economy and society. National Gravimetry Datum has to be reestablished, and National Geodetic Coordinate System has to be improved and updated, i. e. to establish a unified national geocentric 3-dimentional coordinate system and to improve the accuracy of the coordinates of astro-geodetic network.