Method of Optimal Fitting of Existing Lower-Class Leveling Control Networks to Modernized National Higher-Class Networks

Abstract

The proposed method of optimal fitting of the existing lower-class leveling control networks to the modernized national higher-class networks is carried out in two stages. In the first stage, the network is fitted to the maximum possible congruent reference points using robust least-squares adjustment methods. At this stage, the outlier reference points are detected. The reason why outliers appear is usually the vertical displacement of the reference points in the long time period between measurement of the existing network and the modernization of the reference network. In the second stage, the network is fitted to the detected outlier reference points by remeasuring the height differences around these points. A sequential optimal method of design and an online adjustment of the remeasured height differences is proposed. In this way, the potential displaced points of the existing network located around the outlying reference point are also detected and updated. Finally, the network is adjusted and fitted to all reference points of the modernized national control network.