Adjustment of Leveling Network by Information Spread Estimation

It is supposed that observations obey a certain distribution in all the methods of parameter estimation nowadays.But in the practical surveying, due to the different observation conditions, the observations obtained under different observation conditions may obey different distributions. So the supposition is not true.To solve the problem, Wang(1999) has developed an estimation method called information spread estimation, which is a very good estimation method for one parameter.But when the parameters are over one, the estimation method is not suitable.To apply information spread estimation to the adjustment of leveling network, this paper presents a method to use the special feature of leveling.By use of the method information spread estimation can be applied to the adjustment of leveling network conveniently. The results of the adjustment of a leveling network show when gross error is not included in the observations the estimation results obtained by information spread estimation are the same as that by least square estimation. When some gross errors are included in the observations the estimation results obtained by information spread estimation are more effective than the estimation results by least square estimation. So the method presented in this paper is a very useful method for leveling network adjustment.