�Լ��ִ�ѧ�˳���̽��ѧʵϰ����Ϊ�������� EGM2008 ������ģ�ͣ����ö������桢�ƶ����ߡ���С�������á����������ͷ������Ȩ������ֵ���������˲�ͬ GPS ˮ׼���ܶ�����µ�ˮ׼��ģ�ͣ������ö���ˮ׼����������֤�˼��㾫�ȣ������˸�ģ�͵��ʶ��ԡ��������������������ֵ���ľ��Ⱥ��ȶ�����ߣ�������ƶ����߷�����С�������÷�; ����������ϵľ�����ͣ��������Ȩ�������ȶ����������㷨�����������о������� GPS ˮ׼���� 20 km ʱ������ EGM2008 ģ��ȷ���Ĵ��ˮ׼�澫���� 0. 1 m ����; �����õ��� GPS ˮ׼���������ˮ׼��ģ���ܴﵽ 14 cm����ȫ������ֱ���������µ�ʯ����̽����Ҫ��

Taking the network of Xingcheng geophysical teaching and practicing area of Jilin University as a case��we calculated the geoid model with different point density using quadratic surface fitting��moving curve fit- ting��inverse distance weighting interpolation��cubic spline interpolation and least square collocation based on EGM2008�� The precision of the normal height was validated by the second order leveling�� The applicability of model used in geophysical prospecting survey was analyzed�� The results indicated that the cubic spline interpolation has the highest precision and stability�� The moving curve fitting and least square collocation also have high preci- sion and stability�� The quadratic surface fitting has the lowest precision and the inverse distance weightinginterpola- tionhas the lowest stability�� All the algorithms indicated that in the studied area when the mean interval of calculat- ing points is 20 km��the precision of the geoid model which based on EGM2008 is less than 0. 1 m�� When calculat- ed with single GPS leveling point the precision of the model is 14 cm��which completely met the requirements of survey in petroleumgeophysical prospecting with different scales��