Research On Interpolation Method Of Tidal Data

Tide phenomena, closely related to human life, and also fast and accurate tide forecasts are now being a significant demand. Harmonic analysis method is the main method of tidal analysis and forecasting. Although the calculation result is great, the data strictly request and the data processing process is cumbersome. In order to solve the problem of data processing in tidal analysis and forecasting, this paper studies the interpolation method of high and low tide data, and the method of high and low tide and tide level respectively. It is proposed that several clear, simple and effective tide data processing principles can put out.Firstly, the tide composition of different tidal types is analyzed, and the characteristics of high and low tide data are analyzed too. In order to obtain the tide level, the interpolation function of all - day tide and half - day tide is constructed respectively. In particular, the effect of shallow tide is discussed, and the time transformation function is proposed and established. The interpolation results can reflect the influence of shallow tide and improve the interpolation precision.In the study of high and low tide time method, the first three tide data with non-monotonic change is used to construct the parabola,and its vertex can be used as the approximation of high and low tide. And then consider the two sides of the adjacent point contains high and low tide data information, combined with the two points the before and after tide were to build a new parabola,with the new vertex to modify the original results, taking its temporal and spatial characteristics into consideration, the weight combination is established, carrying out the time and space interpolation,results show that the accuracy of the interpolation result is improved. In addition, an intuitive method is proposed in this paper and applied to the forecast. The results show that the prediction error is within the range of permissible error, which can be used as a fast,effective method of solving high and low tide question.Finally, in order to compare the stability and precision of the method, the interpolation results of this method are compared with the results of the Hermite interpolation and the binary-interpolation method. The results show that the accuracy of the interpolation method is improved compared with the contrast method. It laid a good foundation for the study of tide analysis and prediction.