The values of analytical continuation at different depths from the potential field downward constitute the continuationfield, on which the principal component analysis is made.
位场向下在不同深度上解析延拓的值构成延拓场，可对延拓场进行主成份分析。
2
The applications of vector gravity on the determination of the earth's gravity field are described, including the downward continuation of vector gravity and determination of the local geoid.
论述了重力矢量在确定地球重力场方面的作用，包括重力矢量的向下延拓和局部大地水准面的确定。
3
The key to all-dip wave field migration using finite-difference method lies in the continuation direction of wave field.