结合DNSC08-GRA模型中的美国近海测高重力数据,分析比较五种Stokes核函数的计算精度。结果表明,在测试区域,改进的核函数较球形Stokes核函数在精度上有了明显的提高(约3.4 cm);而各改进核函数之间差异不明显。利用GPS/水准数据进行检核发现,拟合前后的大地水准面约有1.17 m的系统差,拟合后标准差减小约7 cm。
The accuracy of different kernels are compared with each other by using the gravity data along the offshore of American sea in DNSC08-GRA model. As the results show, in our test region, the modified Stokes ker- nels can improve the accuracy by 3.4 cm compared with the spherical Stokes kernel, while the difference between different modified kernels is tiny. When verifying the results with GPS/leveling data, it demonstrates the existence of a 1.17 m systematic variation between the geoid fitting before and after. Besides, all the computing accuracy can improved by 7 cm after fitting.