GPS, normal height, geodetic height, non-grid data, terrain effect.
2
如何将GPS大地高转化咸水准高程,并使其保持一定的精度,一直是人们研究的热点。
So it's always a hot topic how to transform GPS ellipsoidal height into level elevation and to keep certain accuracy.
3
指出GPS大地高与正常高之间的转换关系较难确定是限制GPS高程应用的主要原因。
It is more difficult to confirm the transformation relationship between geodetic height and normal height. This is main reason of restricting application of GPS height into use.