应用GPS技术生成DTM及其分析

为了获得各种地面工程数据管理的基础，建立DTM（数字地面模型）是一项主要工作，多数DTM来源于摄影测量的成果。该项研究是在地形开阔的农村地区应用GPS高程测量成果，并依据已有的地形图上信息来生成参考DTM。在研究中，测试了该参考DTM的精度和可靠性，进行了地图比较，通过地图数字化把他们转换为数字形式。经过现场测试，确定当地大地水准面转换参数，分别采用该地区的两个DTM（数字地面模型），最后通过对传统方法和GPS技术建立的两个DTM的分析和比较，得出了有关可靠性等方面的结论。

Establishment of DTM by using GPS and its analysis

In order to obtain DTM(Digital Terrain Model),which is the principal work for data processing in various engineering on ground,some study is carried out on site,but a majority of DTM results from photogrammetry.The research objective in our study is country open land and the digital terrain model is crested from the information on maps.A couple of DTM in the broad area are established by using the classical method and the GPS technique with the determination of geoid parameters on site,and then the analysis and comparison are undertaken based on the elevation differences of the two DTMs and some conclusions about reliability and precision are drawn.