Online Multi-Scale Representation Of Geo-Spatial Data Based On Wavelet Analysis

It is an important and frontier problem about multi-scale handling and representation of geo-spatial data in GIS. It has to resolve how to derive the different representations of the geo-spatial data because the different requirements of applications and analysis from users. This paper formulates briefly the basic principle of multi-resolution analysis (MRA) on wavelet transform at first, and describes a model for multi-scale handling of spatial data based on MRA of wavelet; then the first generation wavelet algorithm and the second generation wavelet algorithm are used to compile the DLL which turn DEM data into multi-scale representations in this paper. The DLL can realize wavelet transformation at integer scale and fraction scale.This paper is divided into five chapters and one brief introduction.The brief introduction describes the contexts about this paper and the general thoughts.The chapter one is introduction. It expounds the scientific significance and necessity about the problem and the application of wavelet analysis. And it recites the general aim and the main contents of the paper.The chapter two is the theory of wavelet analysis. It briefly reviewed the application and development history of wavelet analysis. This paper focuses on wavelet multi-resolution analysis, Mallat algorithm which is pyramid-structured, and the second wavelet transform algorithm based on lifting-scheme.The chapter three is multi-scale representation of terrain based wavelet analysis. It briefly recites the multi-scale issue and varying-scale GIS of geo-spatial data, presents and realizes a multi-scale representation model using the technique of wavelet analysis(including the first generation wavelet algorithm, the second generation wavelet algorithm, border processing, thresholding and choice of wavelet base). The multi-scale representations may be continues between the scales and backwardly.The chapter four is experimental results and estimation. Experimental software system is introduced, including its components composed of many function models and development environments. And taking many practical geo-spatial data as examples of multi-scale handling and representation, we validate the correctness of the relative theories, principles and methods that we represent above.The chapter five is conclusion and prospects. We summarize the whole paper and represent the issue to be studied in the future.