The Implementation Of Tide Harmonic Analysis Forecasting And Datum Calculation Software And Application In South China Sea

Ocean tide is a natural phenomenon prevalent in the coastal areas,and a variety of analytical methods have been developed through the study of long-term tidal data and satellite altimeter data. The vertical datum is the basis for ensuring the construction of surveying and mapping. The establishment of marine vertical datum depends on the processing and analysis of tide data. Therefore, marine tide analysis and vertical datum are the important contents of marine surveying and mapping.This paper briefly introduces the basic theory of tide, introduces the concept of tide, type, static theory, harmonic analysis theory and least squares solution method and tide prediction. Some of the commonly used global tide model and suitable for China's coastal watershed model of the relevant information are listed. The average sea surface and the chart depth datum are two major oceanic vertical datums and given the methods of model establishing.The application program with good interaction interface will bring great convenience to the tide analysis and the datum calculation. Based on the mixed programming technology, this paper designs and develops the application software with both good program interface and fast calculation characteristic.It's main functions including: tidal data harmonic analysis and tide forecast and based on NAO.99b?DTU10?CSR4.0 & NAO.99Jb model tide forecast; the calculation of the datum depth of the above four tide models is developed.The average sea surface height calculation based on the DTU15 model is developed. In order to facilitate the interactive operation, the GMap.NET map base map is designed. Overall, the design goals are met.For the 18 tide stations tide data around the South China Sea, the tide harmonic analysis and calculation, the tidal type of judgment.The influence of the zero tide drift on the harmonic analysis results under different tidal types is analyzed. Four types of sites are analyzed, and the integrated error of the main tide of the 30cm zero drift is 0.16-0.69cm,which indicates that the result is not affected consider. The influence of different observation time on the harmonic analysis was analyzed by the moving average method. At the time of less than 6 months, the comprehensive error of the quarter tide was 1 cm or so, which indicated that the analysis data of less than 6 months were unstable. Analysis of four tide models to calculate the theoretical depth of the datum in the South China Sea waters applicability, using NAO.99b to build with a higher accuracy. Through the revision of the model, the theoretical basis of the South China Sea area is obtained, and the verification sites around the South China Sea are evenly selected. The deviation is less than 10cm,which indicates that the model is reliable. The deviation model of DTU15 average sea surface model and the theoretical depth datum of the South China Sea is constructed, which provides the data source for vertical reference conversion.