Detecting Gross Errors Of Height Measurement And The Stability Analysis Of Height Control Network

There have been more than forty years since the theory of gross error was advanced. Its importance in survey data processing becomes more and more obvious. In height measurement, errors are inevitable. However, gross errors seriously affect the precision of data processing, especially to the adjustment methods that have weak resistivity. Therefore, it is important to study the methods of detecting and eliminating gross errors and to develop relevant software.The first gradation height control network is the base of construction survey. The stability of control points directly influences the quality of construction survey and engineering construction. So it has practical significance to study methods of stability analysis and develop corresponding software.There are several researches in this paper as follows according to gross error elimination of height measurement and stability of height control network:1 Combined with the data of the height control network of Sutong bridge , the theory of data detecting is studied in order to detect gross error and compare their effects.2 The selecting power iteration method is an application of robust estimation theory. It is used to eliminate gross errors of the data of the height control network of Sutong bridge.3 The combination of linear program theory and robust estimation theory is used to detect and eliminate gross errors of leveling data.4 Robust estimation theory is applied to the simulation of GPS height to eliminate gross errors.5 Discrete wavelet transform is used to analyze settlement surveying sequence. Multi-resolution analysis is used to decompose and reconfigure the data of deformation observation, and it can effectively separate the errors and obtain the deformation curve which can be disposed by wavelet transform.6 There are several height control bases which should be chosen in term of different principles. Several methods for checking point stability and integral stability of control network at the same base are studied in the paper.7 Average clearance inspection method, t inspection method and blocking clearance inspection method are used to analyze the point stability and the integral stability of Sutong bridge's height control network.8 The software which can eliminate gross errors of leveling process and analyze stability of height control network is developed. VB is used to complete the software's interface and realize the importation of data. MATLAB is used to edit each subprogram which realize every function. And then, VB invokes MATLAB to implement eliminating gross errors and stability analysis.