Research On Measurement Method Of Map Spatial Information

The quantitative measurement of the quantity of map spatial information is an important research direction in the field of map cartography.The linear target elements play an important role in the graphic expression of map elements,and the curves account for more than 80%of the map graphics.Many scholars have put forward valuable algorithms for measuring the amount of information in map space,but these algorithms all have some limitations.Therefore,through the analysis of the research status and development trend of the measurement method of map spatial information measurement,this paper selects the linear target as the main research object.Firstly,based on the information entropy from the angle of linear target bending,the geometric information of the linear target is designed,moreover the linear target is based on the fractal theory.The algorithm of volume information measurement is improved.1)Introduced the related concepts of information theory and fractal geometry,then summarized and analyzed the definition of information in different fields,pointed out the nature of the diversity and difference characteristics of information,and systematically studied the definition of map spatial information,the classification of map spatial information,and the map space letter with the characteristics of cartography.The measurement methods and criteria of interest volume are introduced briefly,and the linear target elements on the map are briefly introduced.2)Based on Shannon information entropy,we measure the geometric information of linear objects from the perspective of map diversity.Taking the linear target as the research object,based on the spatial cognition,the geometric information of the linear target is classified from three aspects of the complexity,diversity and the difference of the adjacent relationship between bending,and the ratio of bending degree(f_d)and curved area ratio(f_s).As a quantitative description of the geometric shape index,three sets of linear targets are designed to measure the space geometric information,and the experimental results are analyzed to verify the correctness of the algorithm.Then,a set of real map data is selected to measure the spatial geometric information,and the experimental results are analyzed to verify the feasibility of the algorithm.3)Adopting the fractal theory,we use the buffer method to measure the overall information of linear objects from the complexity of maps.Based on the fractal theory,a modified buffer method is proposed on the basis of the fractal theory,and the fractal dimension is obtained.The fractal dimension is used to express the spatial information of the linear target.On the basis of this,the fractal dimension of the Koch curve is calculated.The correctness of the method is then applied to a set of actual map data to calculate the fractal dimension,and the experimental results are analyzed to verify the feasibility of the algorithm.