基于移去计算恢复技术(RCR),结合中国近海区域Sandwell测高重力数据,分析了VK和FEO核函数不同阶数条件下,球冠半径大小对残余大地水准面结果的影响。结果表明,在本测试区域,当核函数阶数较大时(P=L=90和P=L=120),球冠半径的增加对残余大地水准面的影响不显著。综合低阶核函数和较高阶核函数的计算结果,球冠半径为3°是一个较优参数。利用GPS水准数据对计算结果进行检核表明,采用改进的椭球核函数比球面核函数计算精度可以提高1.5cm。
The effects of cap size on residual geoid are analyzed for different order of VK and FEO kernels using Sandwell’s gravity anomaly along the offshore of China Sea based on remove compute and recovery technology.The results demonstrate that the spherical cap radius increases had no significant influence on the residual geoid if a higher order of the kernel functionswas applied in our test region,for example,P=L=90 or P=L=120.From this study,a cap size of 3° is an optimal parameter when the results from the low or high order of kernel are compared and analyzed.The verification of geoid using GPS/Leveling data showed that the modified kernels could improve the precision with 1.5 cm in contrast with the results from spherical Stokes kernel.