On the use of Australian geodetic datums in gravity field determination
On the use of Australian geodetic datums in gravity field determination
复制标题
论澳大利亚大地基准在重力场测定中的应用
DOI：
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发表时间：
1995
期刊：
影响因子：
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通讯作者：
W. Featherstone
中科院分区：
文献类型：
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作者：
W. Featherstone
在任何重力大地水准面计算之前，重力和地形数据的处理至关重要。如果重力或地形数据或两者中仍然存在误差，这些误差将传播到随后确定的重力大地水准面中。本文讨论了水平基准和垂直基准对重力折减的影响，并由此讨论了重力大地水准面。自由空间重力异常应在澳大利亚大地基准坐标转换后，在正常椭球面上计算，并结合二阶自由空间简化。它们的综合效应可以达到-0.120mgal或估计的-12cm的大地水准面。此外，AHD和大地水准面之间的分离对重力确定的大地水准面有影响。综合海洋学和水准测量估计，这种影响在大地水准面上可达0.216毫伽和22厘米。如果采用这种严格的重力数据准备，可以预期在由此产生的重力大地水准面的所有波长中厘米改进。
The treatment of gravity and terrain data prior to any gravimetric geoid computation is critical. If errors remain in the gravity or terrain data or both, these will propagate into any subsequently determined gravimetric geoid. The effects of horizontal and vertical datums on gravity reduction and, hence, the gravimetric geoid are discussed. Free-air gravity anomalies should be computed on the normal ellipsoid, after a coordinate transformation from the Australian Geodetic Datum, and incorporate a second-order free-air reduction. Their combined effect can reach -0.120mgal or an estimated -12cm in the resulting geoid. Also, the separation between the AHD and the geoid has an effect on the gravimetrically determined geoid. A combined oceanographic and levelling estimate implies that this effect can reach 0.216mgal and 22cm in the geoid. If this rigorous gravity data preparation is employed, centimetric improvements can be expected in all wavelengths of the resulting gravimetric geoid.