作者：张胜利

2009年12月25日，以中国工程院院士宁津生为组长的专家鉴定组，对由内蒙古包头市规划局申请立项，市政府投资，包头市测绘院联合武汉大学测绘学院、国家测绘局第一大地测量队共同承担完成的包头市高精度三维GPS控制网及似大地水准面精化项目进行了鉴定。

　　专家们听取了项目汇报，进行了现场测试、质询后认为：包头市高精度三维GPS控制网及似大地水准面精化项目布网结构合理，点位分布均匀，数据处理模型严密，计算方法科学，在数据处理中综合了多种精密数据处理技术，获得了似大地水准面精化精度优于±1cm的高精度成果，达到了项目设计精度要求。一致同意项目通过鉴定。

　　包头市高精度三维GPS控制网的建立及似大地水准面精化项目，从2008年3月开始立项到2009年10月提交全部成果，历时一年半时间。该项目是包头市基础测绘“十一五”规划项目，也是包头市现代测绘基准体系建设的主要内容。项目建设是在国家空间坐标基准框架的基础上，利用大地测量的高新技术手段，在包头市原有平面成果资料和水准、重力资料等测绘成果的基础上，按照统一规划、整体设计的原则，布设覆盖全市域集平面、高程、重力场信息于一体的综合性基础控制网，形成由大地基准、高程基准和重力基准等组成的高精度、三维地心、实用的包头市现代测绘基准体系，为“数字包头”建设和大比例尺测图等测绘工程提供了统一的空间定位基准。该控制网共建二等水准点51个，控制面积2000平方公里以上。该项目在对测区内现有控制资料、重力资料和地形改正资料分析的基础上，完成了GPS框架网、C级网和二等水准的数据处理，进行了似大地水准面精化及包头市地方坐标系与国家坐标系的转换，开发研制了坐标（ITRF97框架、1954年北京坐标系、1980西安坐标系、包头地方坐标系）转换软件和似大地水准面精化成果计算软件。

　　该项目的完成，对加快“数字包头”、“电子政务”等信息化工程建设步伐，改善传统测量模式、减轻野外测量劳动强度、提高测量成果质量、统一包头市测量基准、满足大比例尺测图基础控制的需求，推进城市现代化建设、发展区域经济具有重要作用，应用前景非常广阔。

December 25, 2009, with China Academy of Engineering, Ning, head of the expert appraisal of life for the group, right from the Inner Mongolia Baotou Municipal Planning Council will consider applications project, the municipal government investment, Baotou City, Surveying and Mapping Surveying and Mapping, Wuhan University College of the Joint Institute, the State Bureau of Surveying and Mapping section shared a land survey team in Baotou complete three-dimensional high-precision GPS control network and the quasi-geoid refinement projects were identified.

The experts heard reports of the project carried out field tests, the question after that: Baotou City, three-dimensional high-precision GPS control network and the quasi-geoid project refined fabric network structure is reasonable, points are evenly distributed, data-processing model is tight, and the calculation method of science in the data processing integrated a variety of sophisticated data processing techniques, to obtain a quasi-geoid refinement accuracy of better than ± 1cm high-precision results of the project design to achieve the required precision. Unanimously agreed that the project passed appraisal.


Baotou City, three-dimensional high-precision GPS control network establishment and quasi-geoid refinement project, from project began in March 2008 to October 2009 to provide all the results, which lasted a year and a half. The project is based in Baotou city mapping "Eleventh Five-Year Plan" project is a modern surveying and mapping in Baotou city, the main elements of the base system. Project construction is in the national spatial coordinate reference frame, based on the use of high-tech means of Geodesy, in Baotou city, the information on outcomes and quality of the original plane, gravity surveying and mapping information, etc. Based on the results, in accordance with unified planning and overall design principles, laid covering the city's domain sets plane, elevation, gravity field information based on the integrated control network formed by the geodetic datum, elevation and gravity reference base composed of high-precision, three-dimensional center of the earth and practical reference Baotou modern surveying and mapping system for the "Digital Baotou" construction and large-scale mapping projects such as surveying and mapping provides a unified spatial orientation reference. The control network build a 51-point second-class level, control over an area of 2,000 square kilometers. The project area in the existing control test data, gravity data and topographic correction of data analysis, based on the framework for the completion of the GPS network, C-class network and the second level of data processing, conducted a quasi-geoid refinement and Baotou City, state of local coordinate system and coordinate system conversion, developed the coordinates (ITRF97 frame, coordinate system in 1954, Beijing, 1980, Xi'an coordinate system, Baotou local coordinate system) conversion software, and quasi-geoid refinement results of calculation software.


The completion of the project, to speed up the "digital header", "e-government" and other information projects to the pace of improvement of the traditional measurement mode, reducing the labor intensity of the field measurements to improve the quality of measurement results, unified Baotou benchmarks to meet the large-scale mapping basic control needs, promote urban modernization, the development of regional economy has an important role in very broad application prospects.