A Comparative Study On The Combination Model Of Local Geoid

Study of combined model in Local geoid refining Geoid refining is one of the important contents of geodesy, geophysics and other interdisciplinary research, but also a basic work for surveying and mapping.Specific to research status of China’s geoid refinement, This paper will explore china’s current problems in using different observed data to refine geoid, there are still issues to discuss and propose practical approaches.At first, this paper describes Objective and Significance and of geoid refining, the current study and development at home and abroad, followed by a brief overview of the basic principles and a variety of methods on the refinement. The paper focuses on the law of gravity and GPS geometric standard fitting. Through careful study of various model structures and combination with different examples of calculations of engineering examples, the paper aim to understand and grasp the scope of the model and adapt to a variety of features to fit the model. Furthermore, the paper uses the algorithms of combined model, combined model theory and Removed to restore law theory, Model data of the Earth’s gravity field and GPS altitude figures to get comprehensive and superimposed combined model data. By analyzing error sources of geoid refining, verificating the engineering study, the paper summarizes the stability and adaptability to different terrain of a variety of single model and combined model of. The paper will provide meaningful information in proposing the future local GPS combined elevation model used in production practices selected.