通过大港验潮站坐标确定我国高程基准的垂直偏差

确定局部高程基准相对大地水准面的垂直偏差是统一全球高程基准的重要途径。本文的目的是通过大港验潮站坐标直接确定我国高程基准的垂直偏差。首先给出通过大港验潮站坐标确定我国高程基准垂直偏差的基本原理，然后介绍测定大港验潮站平均海面坐标的方法及过程，接下来通过EGM2008和EIGEN-6C4重力场模型计算出的我国高程基准面的重力位，进而推算获得垂直偏差，并与我国东部地区GPS/水准数据的计算结果进行了比较。经分析发现，EGM2008模型计算结果的可靠性要好于EIGEN-6C4模型；利用大港验潮站坐标计算得到的我国高程基准相对大地水准面的垂直偏差为0.344 m，比利用我国东部261个GPS/水准点数据计算获得的偏差值小0.006 m。

Determination of the Vertical Deviation for China Height Datum with Coordinates of Dagang Tidal Gauge

Determining the vertical deviation for a local height datum relative to the geoid is an important approach to the unification of the Global Vertical Datum. In this paper, we aim at direct determination of the vertical deviation for China Height Datum with the coordinates of Dagang Tidal Gauge. First, the principles for determination of the vertical deviation with the coordinates of Dagang Tidal Gauge are introduced. Then the methods and the processes for measuring and calculating the coordinates of Dagang Tidal Gauge are elaborated. Next EGM2008 and EIGEN-6C4 models are used to calculate the gravity potential with the coordinates of Dagang Tidal Gauge, and the results are compared with those obtained with GPS/Leveling data. It is found that the gravity potential obtained from EGM2008 model is more reliable than that from EIGEN-6C4 model, and the vertical deviation for China Height Datum with the coordinates of Dagang Tidal Gauge is 0.344 m, which is 0.006 m smaller than that with GPS/leveling data.