天津港似大地水准面的精化

Refinement of the geoid in Tianjin port

基于天津港基础控制测量成果与EGM2008模型,采用多面函数拟合法,进行天津港三大港区的似大地水准面精化,并结合已有成果进行精度分析。结果表明,天津港似大地水准面精化的模型检核精度为±7 mm,港区内高程异常跨度为0.622 m,高程异常偏差由西向东逐渐减小,南北相差不大,高程异常等值线整体沿南北走向。经工程实践验证,基于天津港似大地水准面精化模型,港区内可用D级GNSS高程测量代替三、四等水准测量,可用网络RTK高程控制测量代替四等水准测量。

Based on the Tianjin Port’s basic control survey results and the EGM2008 model, the multi-faceted function fitting method is used to refine the quasi-geoid surface of the three major port areas of Tianjin Port, and the accuracy analysis is carried out based on the existing results.The results show that the accuracy of model checking of the refined geoid of Tianjin Port is ±7 mm, the span of elevation anomaly in the port area is 0.622 m, and the deviation of elevation anomaly decreases gradually from west to east, and the difference between north and south is not large, and the height anomaly is equivalent.The line runs from north to south as a whole.It has been verified by engineering practice that based on the refined model of the similar geoid in Tianjin Port, D-level GNSS elevation surveys can be used in the port area to replace third and fourth-level leveling surveys, and network RTK elevation control surveys can be used to replace fourth-level leveling surveys.