An alternative expression for the variance factors in using Iterated Almost Unbiased Estimation

Abstract.

An alternative expression has been derived for the variance factors when estimating weights according to the Iterated Almost Unbiased Estimation (IAUE) technique. A variance factor can be approximately estimated by finding the ratio of the group redundancy numbers at any two successive iterations. The numerical example of the first-order leveling network of Taiwan indicates: that stabilization of the redundancy number of an observation occurs as the variance factor associated with it converges to unity; that variance factors tend to approach unity for individual groups with large redundancy; and that for those variance factors which fail to converge to unity, the redundancy numbers decrease monotonically as the iteration proceeds.