Additional comments on "Multistage least-squares parameter estimation"

The purpose of this correspondence is to call attention to other solutions to the problem addressed in the above paper,[1] that of adding or deleting parameters or measurements from a given linear model. The solution algorithms proposed in the article are numerically ill-conditioned and are less efficient, in terms of both computational and storage requirements, than the methods described here. Several numerically stable, compact, flexible, and efficient algorithms for analyzing the parameter estimation problem are described and others are referenced.