Research and Development of Methods and Instrumentation for the Calibration of Vertical Angle Measuring Systems of Geodetic Instruments

Abstract

This research deals with the methods and instrumentation for calibration of vertical angle measuring systems of geodetic instruments. Two different methods are proposed in the thesis. First method is based on the vertical angle measuring system calibration using trigonometric method where 1 m reference scale with 1mm grating is utilized. Two ways of application of this method are analyzed in the thesis as well as uncertainty sources and their impact on measurement results are provided in the table of the uncertainty budget. Another method for vertical angle measuring system calibration is based on the new setup of the reference means. New proposed apparatus is designed to fit the instrument under calibration in horizontal position. Therefore, this setup enables to perform calibration of vertical angle measuring systems using horizontal angle measuring system calibration techniques. The special mirror mount was attached to the telescope of the calibrated instrument and the change of the telescope position was measured by the electronic autocollimator. The analysis of the uncertainty budget is presented in this thesis. The dissertation consists of introduction, 3 chapters, general conclusions and references. The introduction reveals the topicality of the thesis, investigated problem and object of the research. The aim and tasks as well as research methodology, scientific novelty, practical significance of the results and defended statements are also presented in the introduction. Chapter 1 revises scientific papers on the subject of the dissertation. Analysis of standards, methods and instrumentation for the calibration of angle measuring systems are provided in this Chapter. Chapter 2 describes the main principles of two proposed methods. The instrumentation and measurement procedure are analyzed as well as uncertainty evaluation model is designed. Chapter 3 is focused on the experiment of the practical application of both proposed methods. The uncertainty sources are analyzed and specified in the tables of uncertainty budgets. The experimental results of the calibration of vertical angle measuring systems of the total station are revealed. Research results are presented in 7 publications of scientific journals: 3 publications in journals indexed in ISI Web of Science data base with the impact factor, 4 – in other international scientific journals indexed in SCOPUS, Compendex databases. 5 papers are published in the proceedings of international conferences. 1 national patent regarding method for calibration of vertical angle measuring systems using reference scale was registered in the State Patent Bureau of the Republic of Lithuania.