基于 CGCS2000建立珠海市城市相对独立坐标系统的探讨

CGCS2000（2000国家大地坐标系）建立城市城建坐标系，对各地区均是一次坐标系整合提升的好机会，通过建立高等级、多坐标系、统一的GNSS控制网，建立基于CGCS2000的城市城建坐标系统，同时解决新旧坐标系统转换的问题。由于城建坐标系需要考虑边长投影变形的问题，设置自定义中央子午线是一种简便的解决方法，此种有特殊定义的坐标系统仍然属于一种相对独立坐标系统，这种独立坐标系统与国家坐标系统保持了最大的一致，可以无精度损失地、方便地转换到国家坐标系统中。本文就建立基于CGCS2000的珠海市相对独立坐标系进行探讨，并对珠海新旧坐标系转换可能产生的问题及处理方法进行探讨。

Discussion about the Construction of City Relatively Independent Coordinate System of Zhuhai Based on CGCS2000

Based CGCS2000（2000 National Geodetic Coordinate System ）establishing urban coordinate system ,is a good opportunity to upgrade about coordinate system ,through the establishment of GNSS-control network of high-level, multi-coordinate system,establishing coordinate system ,at the same time solve the problem of new and old coordinate system transformation ,Due to the coordinate system need to consider the deformation of side length problem ,Set the cus-tom central meridian is a simple solution ,this has a special definition of coordinate system still belongs to a kind of rela-tively independent coordinate system , this independent coordinate system and national coordinate system can keep the biggest consistency ,without loss of precision ,convenient to transition to the national coordinate system ,this paper is built based on CGCS2000 zhuhai relatively independent coordinate system were discussed ,and the zhuhai coordinate system transformation between the old and the new possible problems and solutions are discussed .