DISCUSSION ON RELATION BETWEEN DATUM CONDITION AND COORDINATE SYSTEM
基准与坐标系之间关系的探讨

Because the free net adjustment model is rank-defect,the normal equation derived with the LS method has an infinite number of solutions.Geodetically,the configuration of geodetic network can not be fixed.In order to obtain a unique configuration of geodetic network,some datum conditions should be introduced into.In other words,coordinate system will be determined if datum is given.Therefore datum must involve some information for defining coordinate system.Three kinds of datum conditions and a general solution in free geodetic network adjustment are presented here,and a formula about the relation between datum condition and coordinate system is test through an example.