SEQUENTIAL ALGORITHM ON VARIANCE COMPONENT ESTIMATION IN JOINT ADJUSTMENT OF VARIOUS OBSERVATIONS
Zhang Chaoyu~(1), Tao Benzao~(1) and Shi Jin~(2)1)Laboratory of Geospace Environment and Geodesy, Ministry of Education, China,School of Geodesy & Geomatics, Wuhan University,Wuhan4300792)Institute of Planning & Design of Civil Servant Residential Area of Luoyang,Luoyang471000
On the basis of Helmert's formula for variance component estimation, a sequential algorithm for joint adjustment of various observations is put forward in this paper. This method is different from the available methods which let the post-adjustment weight variances corresponding various observations be identical wholely.However,it is sequential adjustment, doing the variance component estimation after the adjustment of each class of observations, and then in proper order make the post-adjustment unit weight variances equal to each other. It conquers the disadvantages of using a lots of memory and calculating complicated matrices. There is not any approximate processing of the original Helmert's formula without saving extra historic data beyond sequential adjustment. This algorithm is very suitable for programming on computers.