新一代全球海底地形模型BAT_WHU2020

A new generation of global bathymetry model BAT_WHU2020

本文利用由多源卫星测高资料计算的新版全球重力异常Grav_Alti_WHU,联合船测水深资料,构建了全球75°S—70°N范围的1′×1′海底地形模型BAT_WHU2020。以船测水深、现有模型和多波束测深数据为参考,对模型精度进行了分析评价。结果表明,在中国海域及邻区(104°E—160°E,0°N—50°N),本文模型与船测水深之差值的标准差约70 m,与SIO V19.1模型精度相当,优于ETOPO1、DTU10、GEBCO_08等模型,较此前发布的BAT_VGG模型精度提高了约30%,说明本文模型构建方法可靠、数据处理准确、精度较高。在全球范围内,BAT_WHU2020模型与船测水深之差值的标准差为50~65 m,差值在±200 m范围内的比率超过95%,与SIO V19.1模型精度相当,优于ETOPO1、DTU10、GEBCO_08等模型,较BAT_VGG模型精度提高了27%~36%。以SIO V19.1模型为参考,模型之差的标准差为90~110 m,约90%格网点差值在±200 m以内,约95%格网点差值在±300 m以内,两者一致性良好。最后,讨论了地壳均衡、Parker公式高次项等对成果精度的影响,模型的真实空间分辨率,以及以多波束测深为参考的模型精度问题。分析认为,BAT_WHU2020模型空间分辨率为10~18 km,在马里亚纳海沟、麦夸里海岭地区相对精度为5%~6%。

In this paper,a 1′×1′bathymetry model BAT_WHU2020 in the range of 75°S—70°N is constructed by using the latest version of the global gravity anomaly model derived from the multi-source satellite altimetry data and the shipboard depths.The accuracy of the model is analyzed and evaluated based on ship depths,existing models and multibeam soundings.The standard deviation of the difference between the proposed model and the ship depths in China Sea and its adjacent areas(104°E—160°E,0°N—50°N)is about 70 m,which is equivalent to the accuracy of SIO V19.1 model,superior to ETOPO1,DTU10,GEBCO_08 model,and about 30%higher than the accuracy of BAT_VGG model published before,which shows that the method in this paper is reliable,and the data processing is accurate and the accuracy is high.The standard deviation of the differences between BAT_WHU2020 model and ship depths is about 50~65 m globally,and the ratio of the difference within±200 m is greater than 95%.It is showed that the accuracy of BAT_WHU2020 model is equivalent to SIO V19.1,better than ETOPO1,DTU10,GEBCO_08 model,and improved about 27%~36%from the BAT_VGG model.Comparing to SIO V19.1 model,the standard deviation of the model differences is about 90~110 m,about 90%of the grid differences is within 200 m,and about 95%is within 300 m.Finally,the effects of crustal isostasy and high order terms in the Parker’s formula on the accuracy of the results,the accuracy of the model compared to multibeam soundings,and the spatial resolution are discussed.It indicates that the spatial resolution of BAT_WHU2020 model is about 10~18 km,and the relative accuracy is about 5%~6%around the Mariana trench and Macquarie ridge.