This paper mainly discussed the technology on local rectifying plane coordinate system transformation,coordinate conversion from WGS84 coordinate system to national coordinate system assisted by refined geoid models.

This paper introduced the process of the construction of fiducial system for modern surveying of Wuhan city on the whole,then explained and analysed the data process and test of WHCORS、high accurate GPS reference network、accurate level net and areal geoid refine in Wuhan.

The local refined Quasi-Geoid has been constructed in several regions and widely applied.

This paper,by the example of qingdao gulf bridge measurement control system,introduced gulf bridge first class control network、gulf bridge GPS integrated application system、the method and precision of gulf bridge areal quasi-geoid refine,summaries the key technology and characteristics of this project,qingdao gulf bridge measurement control system is useful for oversize bridge construction.

In the paper,through comparing with the application of serveral geoid models in different area and anal-yzing the accuracy of 1∶10 000 Digital Orthophoto Map Control Point Surveying work in wide area,some useful results that guide to several actual projects can be given.

Using the CQG2000 quasi geoid model developed recently in China,the authors corrected the ellipsoidal height of GPS survey and,as a result,attained a higher accuracy of orthometric altimetric survey.