On the rational evaluation of the relative precision of points
SHI Yi-min~①,ZHU Zi-yang~②(①Department of Surveying,Tongji University ,Shanghai 200092,China;②Resource Department of Guangdong Province,Guangzhou 510500,China)
The evaluation of the relative precision of a point by traditional methods is neither objective nor reliable. The first reason is that impacts of errors of initial data have not been taken into account;the second is the unconformity between the result and the practical purpose.As the reference datum for the precision,the datum for covariance presented by the author is not the same as the datum for coordinates. This theoretical concept possessed practicability,when it is applied to defining the absolute and the relative precision of a point.It is convenient to carry out transformation between the two different datums for covariance.A new method of the rational evaluation of the relative precision is put forward.The effectiveness of the method has been demonstrated by the application to a control network.