Application of Helmert Variance Component Estimation to Surveying of Ballastless Track Railway

Abstract:

The relative accuracy of two consecutive points in the network of ballastless track railway must controlled within 1mm, which means that the reasonable and reliable method should be employed to assess the adjustment accuracy. In adjustment problems, improper stochastic model will affect the adjustment result and its accuracy evaluation. In this paper, we will introduce the construction of the first ballastless track railway from Beijing to Tianjin in China. Then, we will use the Helmert variance estimation method to reasonably determine the weights of directions and distances in adjustment processing, thus achieving the reliable the adjusted coordinates and their accuracies.