广东省邻近海域平均海平面模型订正

Revision of mean sea level model in adjacent waters of Guangdong Province

目前国际上推出了高精度和高分辨率的全球平均海平面模型有法国国家宇航中心(CNES_CLS)、丹麦技术大学(DTU)等,但这些模型普遍存在一个问题就是邻近陆地部分精度较差。本文以DTU18平均海平面局部模型作为研究对象,首先通过提取该模型的广东省近海海域数据进行参考椭球转换统一至2000国家大地坐标系(CGCS2000)参考椭球坐标系作为初步模型,其次结合广东省沿岸18个长期验潮站水位数据和7个短期验潮站水位数据,其中短期验潮站通过同步验潮法计算出多年平均海平面值,最后通过该订正方法可将初步模型值和验潮站多年的平均海平面不符值对初步模型进行订正得到成果模型,并进行精度评估。使提高精度后的广东省邻近海域平均海平面模型在广东省陆海基准统一方面更具有实用价值。

At present,high precision and high resolution global mean sea level models such as Centre National d′Etudes Spatiales(CNES_CLS)and Technical University of Denmark(DTU)have been introduced internationally.However,a common problem of these models is that the accuracy of the adjacent land parts is poor.In this paper,the DTU18 local mean sea level model was taken as the research object.Firstly,the reference ellipsoid was converted and unified to China geodetic coordinate system 2000(CGCS2000)reference ellipsoid coordinate system by extracting the offshore sea data of the model in Guangdong Province.Secondly,the water level data of 18 long-term tide stations and 7 short-term tide stations along the coast of Guangdong Province were combined.In the short-term tide survey station,the multi-year mean sea level value could be calculated by the synchronous tide survey method.Finally,the preliminary model could be revised by using this correction method to obtain the result model and evaluate the accuracy.The improved mean sea level model had more practical value in the unification of land-sea datum in Guangdong Province.