基于EGM2008模型的近海高程传递方法研究

Research on Method for Offshore Elevation Transmission Based on EGM2008 Model

研究了基于EGM2008大地水准面模型的高程传递原理,通过青岛地区已知控制点数据计算得到EGM2008大地水准面模型与我国大地水准面差距,利用EGM2008模型计算高程异常的方法,结合GNSS技术实现高程传递。利用青岛市C级GNSS控制网数据,基于EGM2008模型,采用3种不同的拟合方法,建立了区域高程异常残差场,反演高程异常值与已知控制点高程异常值进行比对。利用青岛市D级GNSS点的数据对构建的格网模型的精度进行检核。结果表明:EGM2008大地水准面模型与我国的大地水准面存在22 cm左右的偏差;基于EGM2008模型的高程传递精度可达厘米级,可用于近海高程传递,几种拟合方法精度相当。

Principle of elevation transmission based on EGM2008 geoid model is studied.The difference between the EGM2008 geoid model and the geoid in China is obtained by calculating the data acquired from the known control points in Qingdao region.By using the EGM2008 model to calculate the elevation anomalies and combining with GNSS technology,the offshore elevation transmission is realized.Based on the EGM2008 model,the GNSS control network data of C level in Qingdao City are applied to construct the regional elevation anomaly residual field using three different fitting methods,and the inversed elevation anomaly values are compared with those from known control points.The accuracy of the constructed grid model is checked by using the data of D-level GNSS points in Qingdao City.The results show that there is a deviation of about 22 cm between the EGM2008 geoid model and the geoid in China.The elevation transmission based on the EGM2008 model can reach to a level of centimeter in accuracy and can be applied to the offshore elevation transmission.The elevation transmission accuracy obtained by different fitting methods can be comparable.